Samsung LCD TV – Service Tips -
Samsung LNT3253: After a few minutes when TV
warms-up picture becomes distorted
Samsung LNT3253HX/XAA LCD TV.
After a few minutes when TV warms-up picture becomes distorted
> 10-15 minutes after you turned on the unit panel warms-up and picture becomes distorted. If you just push the TV's frame picture becomes even more distorted. On the back of the panel the CONTROL ASIC area is very hot. Replace the panel to fix the problem.
After a few minutes when TV warms-up picture becomes distorted
> 10-15 minutes after you turned on the unit panel warms-up and picture becomes distorted. If you just push the TV's frame picture becomes even more distorted. On the back of the panel the CONTROL ASIC area is very hot. Replace the panel to fix the problem.
Samsung: LN32A450_LN32A330: Video will intermittently turn
mostly white
Samsung LN32A450C1DXZA,LN32A450C1HXZA,LN32A450C3HXZA,LN32A 330J1DXZA,LN32A330J1NXZA LCD TV
Samsung LN32A450C1DXZA,LN32A450C1HXZA,LN32A450C3HXZA,LN32A 330J1DXZA,LN32A330J1NXZA LCD TV
Video will intermittently turn mostly white > White display with a faint image of OSD (On Screen Display) and video in the background. Video will intermittently turn mostly white with the OSD barely visible in the background. Even a black image or when the panel should not be showing any video, it is white. I found that one of the sub-boards inside the panel, the boards that the ribbon cable from the T-Con connect to, are not seated properly and the larger SMD capacitors on the board are intermittently making contact with the metal frame of the set, effectively creating a short to ground.
This is one of the panels that are mounted upside down, so the stand mounts just below and behind the panel frame. Any slight pressure from the stand can cause the frame to make contact. In many cases, the TV can be slightly flexed to make this issue occur.
You may see besides a T-Con ribbon cable that the sub-board is not seated properly, and is in fact bowing towards the outer frame. Pulling the frame out slightly, you can see one of the SMD capacitors that can make connection with the frame. Adding felt to the affected area will solve the issue.
Samsung most model: Firmware Blinking in Red at the Top of the Screen
Model/s: Samsung LN32B360C5DXZA,LN32B530P7FXZA,LN32B650T1FXZA,LN32B 460B2DXZA,LN32B540P8DXZA,LN32B550K1FXZA,LN32B640R3FXZA,LN32B457C6HXZA,LN32B450C4HXZA,LN37B 457C6HXZA,LN37B530P7FXZA,LN37B650T1FXZA,
LN37B550K1FXZA,LN40B457C6HXZA,LN40B550K1HXZA,LN40B500P3FXZA,LN40B550K1FXZA,LN40B650T1FXZA,LN40B530P7FXZA,LN40B530P7NXZA,LN40B750U1FXZA,LN40B 540P8FXZA,LN40B610A5FXZA,LN40B630N1FXZA,LN40B640R3FXZA,LN46B650T1FXZA,LN46B530P7NXZA,LN46B 530P7FXZA,LN46B550K1FXZA,LN46B610A5FXZA,
LN46B540P8FXZA,LN46B630N1FXZA,LN46B640R3FXZA,LN46B750U1FXZA,LN52B550K1HXZA,LN52B610A5FXZA,LN52B550K1FXZA,LN52B540P8FXZA,LN52B530P7FXZA,LN52B 630N1FXZA,LN52B750U1FXZA,LN55B640R3FXZA,LN55B650T1FXZA LCD TV.
Firmware blinking in Red at the top of the screen.
> Problem - After changing the main board, I'm now stuck with the firmware text info blinking in RED print at the top of the screen. The unit is stuck in aging mode. To exit, simply hit the menu button on the TV itself.
Samsung LNT4065_LNT5265: With Signal-Blue Screen and Flashing White Short Horizontal Lines
Model/s: LNT4065FX/XAA,LNT4665FX/XAA,LNT5265FX/XAA,LNT4061FX/XAA,LNT4661FX/XAA
Blue screen without signal, with signal -blue screen with flashing white short horizontal lines
> Refit or replace LVDS cable, check if the cable not strangled by the metal cover and loosen up the screws of the cover.
Samsung LNT3242_3232 : Wont Power On
Samsung LNT3242HX/XAA,LNT3232HX/XAA LCD TV
Symptom: Wont power on
TV would not come on. Removed the back and as soon as we did the set came on.
Found glue all on the cables to the smps. Cleaned glue off and cleaned the terminals. Set operates normally.
Samsung LN32A330: The TV takes longer to power on than normal
Samsung LN32A330J1DXZA,LN32A330J1NXZA LCD TV
The TV takes longer to power on than normal
The TV takes longer to power on than normal. You may hear several clicks while the TV attempts to power on.
The electrolytic in the capacitors on the power supply board over time will dry out causing the power supply to shut down during its initial power on cycle.
Samsung: Unit tries to start with melody but cycles off and back on
Samsung LN40A650A1FXZA,LN46A650A1FXZA,LN40A750R1FXZC,LN46A 750R1FXZA,LN40A750R1FXZA LCD TV
Unit tries to start with melody but cycles off and back on
> If the unit tries to turn on and makes the startup melody but then immediately shuts off and starts again, unplug the LVDS cable and apply power again. If the set stays on, replace the T-Con board.
Samsung: Will not turn on, cycles on and off with startup melody, no backlights
Samsung LN52A650A1FXZA,LN40A650A1FXZA,LN46A650A1FXZA,LN52A 650A1FXZC,LN46A650A1FXZC LCD TV
Will not turn on, cycles on and off with startup melody, no backlights
> If the set will try to turn on and the startup melody sounds but no backlight appears and the set cycles off and on every 5 to 10 seconds, unplug the LVDS cable from the T-Con/FRC board. If the set then runs and the backlights come on and stay on, replace the defective T-Con/FRC board.
Samsung LNS4692: No video TV, has backlight and audio. TV will not come on
Samsung LNS4692DX/XAA LCD TV
No video TV, has backlight and audio. TV will not come on.
> Found pico fuse open at cp1 on the T-CON PCB short cp1 TV comes on runs fine. Replace the T-CON PCB.
Samsung: Standby light is on, flashes once briefly then unit attempts to turn on
Samsung LN32A330J1DXZA,LN32A450C1DXZA,LN32A550P3FXZA,LN32A 540P2DXZA,LN32A330J1NXZA,LN32A450C1HXZA,LN32A450C3 HXZA, LN32A300J1DXZA LCD TV
Standby light is on, flashes once briefly then unit attempts to turn on
If the unit will not turn on, but the red standby LED is on and flashes once quickly when the power button is pressed on the remote or the TV, the 2200uf 10v filter capacitor on the SMPS has failed. This capacitor is located in the upper right side of the power supply close to the cable that connects the main board. Visual inspection will normally show that it has a swollen top. Replace capacitor and inspect the others in the filter stage to restore operation.
Samsung: Unit cycles on and off several times before starting
LNT4069FX/XAA,LNT4066FX/XAA,LNT4669FX/XAA,LNT4071FX/XAA,LNT4671FX/XAA,LNT5271FX/XAA,LNT4065FX/XAA,LNT4665FX/XAA,LNT5265FX/XAA,LNT4061FX/XAA,LNT4661FX/XAA
Unit cycles on and off several times before starting
> If the unit will cycle on and off several times before turning on and then playing fine, check the power supply carefully for filter capacitors with bulged tops. Replace the capacitors or power supply to correct the issue.
Samsung: Auto-shutdown on 2008 LCD TV’s
Samsung LN32A330J1DXZA,LN32A450C1DXZA,LN32A650A1FXZA,LN32A 550P3FXZA,LN32A540P2DXZA,LN32A330J1NXZA,LN32A300J1 DXZA, LN40A530P1FXZA, LN40A450C1DXZA, LN40A750R1FXZA, LN40A330J1DXZA, LN40A550P3FXZA, LN40A540P2FXZA, LN40A500T1FXZA, LN46A530P1FXZA, LN46A860S2FXZA, LN46A750R1FXZA, LN46A550P3FXZA, LN46A650A1FXZA, LN46A950D1FXZA, LN46A540P2FXZA, LN46A500T1FXZA, LN46A850S1FXZA, LN46A630M1FXZA, LN46A850S1FXZX, LN46A580P6FXZA, LN52A530P1FXZA, LN52A750R1FXZA, LN52A650A1FXZA, LN52A550P3FXZA, LN52A630M1FXZA, LN52A860S2FXZA, LN52A850S1FXZA, LN52A540P2FXZA, LN52A580P6FXZA.
Auto-shutdown on 2008 LCD TV’s.
> Upon inspections of 2008 LCD TV's we have found that the LVDS (ribbon cable) can cause an auto shut down. Even if the LVDS cable doesn’t look defective try changing it anyway and retest the TV. It is a good practice to carry a few extra LVDS cables in your van for such testing circumstances.
Samsung: Unit tries to start with melody but cycles off and back on
Samsung LN40A650A1FXZA,LN46A650A1FXZA,LN40A750R1FXZC,LN46A 750R1FXZA,LN40A750R1FXZA LCD TV
Unit tries to start with melody but cycles off and back on.
> If the unit tries to turn on and makes the startup melody but then immediately shuts off and starts again, unplug the LVDS cable and apply power again. If the set stays on, replace the T-Con board.
Samsung LNS2651 & LNT3242: Picture is lost, sound OK after MAIN PCB was replaced
Samsung LNT3242HX/XAA, LNS2651DX/XAA LCD TV
Picture is lost, sound OK after MAIN PCB was replaced
> If after replacing MAIN PCB and made all correct setups in "OPTION BYTE" you get the symptoms:
* lost picture after 5-10 min. but sound OK, picture comes back if you restart the LCD but just to be lost again after the same interval or
* Picture is lost intermittently every 10-20 sec. and comes back itself, again sound OK.
You may not have to come back with another Main PCB, this may be corrected just by moving the connection between inverter and SMPS on the SMPS board. If it was on A-CNM803 move it to S-CNM802 or vice versa from S-CNM802 to A-CNM803 on the SMPS board, see picture. If this is not working then use a new MAIN PCB.
This may be applied to other LCD models too.
Samsung LNS4051: Clicking repeatedly TV will not turn on
Samsung LNS4051DX/XAA LCD TV
Clicking repeatedly TV will not turn on
> Found 2 electrolytic 100uf at 16v capacitors on the 5V line C115 and C123 bad. Or replace the power supply.
Samsung: Backlight Failure Testing
Model/s: Samsung LN32B360C5DXZA,LN32B530P7FXZA,LN32B650T1FXZA,LN32B 460B2DXZA,LN32B540P8DXZA,LN32B550K1FXZA,LN32B640R3 FXZA, LN32B457C6HXZA, LN32B450C4HXZA, LN32B540P8DUZA, LN32B450C3HXZA, LN32B460B2DUZA, LN32B360C5DUZA, LN32B550K1FUZA, LN32B530P7FUZA, LN32B450C3HUZA, LN40B530P7FUZA, LN40B550K1FUZA, LN40B457C6HXZA, LN40B550K1HXZA, LN40B610A5FUZA, LN40B640R3FUZA, LN40B650T1FUZA, LN40B630N1FUZA, LN40B540P8FUZA, LN40B500P3FXZA, LN40B550K1FXZA, LN40B650T1FXZA, LN40B530P7FXZA, LN40B530P7NXZA, LN40B750U1FXZA, LN40B540P8FXZA, LN40B630N1FXZA, LN40B640R3FXZA, LN52B550K1HXZA, LN52B610A5FXZA, LN52B550K1FXZA, LN52B540P8FXZA, LN52B530P7FXZA, LN52B630N1FXZA, LN52B750U1FXZA LCD TVs.
Backlight Failure Testing
> Backlight failures can be partial or full failure Check the backlight supply voltage (refer to service manual) If supply voltage is present, use a flashlight behind the television and shine a light through the panel. If the video is working you will see it.
Samsung LNS4041: Unit Continually Cycling On and Off
Samsung LNS4041DX/XAA LCD TV
Unit Continually Cycling On and Off. Set turns on and off in a continuous cycle. Plays the melody each time.
> First, check the power supply voltages, if missing, replace the power PCB. Next unplug the LVDS cable. If the set continues to cycle, replace the main PCB. If the cycling stops, replace the LCD panel. Part numbers are version dependent, so be sure to check the set's version.
Samsung LNT4671 & LNT5271: TV is cycling, the red led blinking and the relay is cycling
Samsung LNT5271FX/XAA,LNT4671FX/XAA LCD TV
TV is cycling, the red led blinking and the relay is cycling sometime TV will come on.
> TV is cycling, the red led blinking and the relay is cycling sometime TV will come on. The Main board replaced, did not fix. This unit was a Refurb, found cable from the main board to the side AV jack was reversed, is not labeled as to direction of use. This cable if reversed will be hot to the touch. Found by removing and replugging and changing direction of cable TV worked. This was tried on both model numbers with the same result.
Samsung: DEAD BACKLIGHT FLASHES ON THEN OFF
Model/s: Samsung LNS4051DX/XAA LCD TV
Symptom: Dead backlight flashes on then off.
UNIT WOULD FLASH ON THEN OFF AND AUDIO WOULD WORK. YOU COULD SEE VIDEO WITH A FLASHLIGHT. SOMETIMES UNIT WOULD STAY ON AND RUN IF YOU CYCLED ON AND OFF MANY TIMES. FOUND BAD SOLDER CONNECTION ON IP BOARD TI801 ON PRIMARY SIDE. RESOLDERED AND CORRECTED PROBLEM.
Samsung: Poor or Intermittent Video
Model/s: Samsung LNS4695DX/XAA,LNS4696DX/XAA,LNS4096DX/XAA,LNS4095DX/XAA LCD TV
Symptom: Poor or Intermittent Video
Cure/Solutions: Check the LVDS cable where it connects to the panel interface board. Be sure that the cable does not have any glue on it. On occasion, the glue can cause a poor connection if it gets into the connector. Remove glue or replace the LVDS cable with BN39-00726A.
Samsung: Half the screen is purple
Model/s: Samsung LNT4065FX/XAA,LNT4665FX/XAA,LNT5265FX/XAA,LNT4061FX/XAA,LNT4661FX/XAA LCD TV
Symptom: Half screen is purple
Cure/Solutions: Half screen is purple. LCD panel controller board is defective. Panel needs to be replaced.
Samsung: Video Stuttering or Hesitation
Model/s: Samsung LNT4071FX/XAA,LNT4671FX/XAA,LNT5271FX/XAA LCD TV
Symptom: Video Stuttering or Hesitation
Cure/Solutions: The customer may complain that the video has a stutter or hesitation when viewing regular programming, either standard definition or high definition.
To fix, go into the customer menu, select Picture, then scroll to Auto Motion Plus 120Hz and select Off.
This enhancement circuit works for some movies, but can introduce severe hesitations and ghosting on regular programming. The customer should also be informed that this does not affect the 120Hz operation of the panel. The panel operates at 120Hz regardless of this setting.
Samsung: Troubleshooting Inverter PCB boards
Model/s: Samsung LNT4061FX/XAA, LN32A450C1DXZC, LN32A550P3FXZC, LN32A550P3FXZX, LN32A450C1DXZX,
LN32A650A1FXZA, LN32A450C1XZD, LN32A450C1DXZA, LN32A540P2DXZA, LN32A450C1XZP, LN32A550P3RXZD, LN40A530P1FXZA, LN40A530P1FXZX, LN40A450C1HXZX, LN40A450C1DXZA, N40A750R1FXZA, LN40A450C1DXZX, LN40A530P1FXZC, LN40A550P3FXZC, LN40A650A1FXZC, LN40A550P3FXZX, LN40A750R1FXZC, LN40A330J1DXZX, LN40A650A1FXZX, LN40A450C1XZD, N40A450C1DXZC, LN40A330J1DXZA, LN40A550P3FXZA, LN40A650A1FXZA, LN40A750R1FXZX, LN40A550P3RXZD, LN40A330J1XZD, LN40A630M1FXZA, LN40A540P2FXZA, LN40A650A2RXZD,
LN40A630M1FXZC, LN40A630M1FXZX, LN40A610A3RXZD, LN40A500T1FXZA, LN40A330J1XZP, LN40A450C1XZP, LN40A650A1RXZP, LN40A610A1RXZD, LN40A650A1FXZD LCD TVs.
Troubleshooting Inverter PCB boards
The inverter PCB is the power supply for the Cold Cathode Fluorescent tubes. The inverter acts exactly like the ballast used in a standard fluorescent light fixture. In the case of an LCD TV, 24 volts from the power supply is applied to a switch mode power supply (SMPS). The SMPS outputs ~1000 Volts to energize the bulbs then the voltage drops to ~ 500 volts for run operation. The SMPS switching frequency is around 90 KHz. The first step for verifying inverter board operation is to confirm the 24 volt supply is present. An oscilloscope can also be used to verify the SMPS circuit is oscillating. Simply holding the oscilloscope probe in the area of the switching transformer will show screen activity if the switching action is taking place. Measuring the SMPS output with standard equipment is not recommended as this is high voltage and at a high frequency.
Samsung: Intermittent LCD Video Troubleshooting
Model/s: Samsung LNT4069FX/XAA, LNT4066FX/XAA, LNT4669FX/XAA, LNT3255HTX/XAA, LNT375HAX/XAA, LNT4042HX/XAA, LNT325HAX/XAA, LNT405HAX/XAA, LNT2353HTX/XAA, LNT3753HX/XAA, LNT2653HTX/XAA, LNT3242HTX/XAA, LNT3253HTX/XAA, LNT4042HTX/XAA, LNT4053HTX/XAA, LNT4071FX/XAA, LNT4671FX/XAA, LNT5271FX/XAA, LNT4642HX/XAA, LNT466FX/XAA, LNT4065FX/XAA, LNT4665FX/XAA, LNT5265FX/XAA, LNT2632HX/XAA, LNT2642HX/XAA, LNT2653HX/XAA, LNT3232HX/XAA, LNT3242HX/XAA, LNT3253HX/XAA, LNT3732HX/XAA, LNT4032HX/XAA, LNT4053HX/XAA, LNT4061FX/XAA, LNT4661FX/XAA LCD TVs.
Symptom: Intermittent LCD Video Troubleshooting
Troubleshooting intermittent video problems can be time consuming, but these tips may help narrow down the cause of an intermittent video problem.
The very first thing to do is to make sure the customer does not have OSD. They can verify this by just pressing Menu or Volume on their TV remote control. If they do have OSD, then the problem is most likely in the source and not the TV.
The next step when encountering an intermittent video problem is to find out if the backlights are on when the set loses video. You can probably obtain this information from the customer before you schedule the call. Ask if they noticed if the screen is completely black or if it is lit up slightly when the video goes out. They may be able to notice it better if they stand at an angle to the TV and turn it on or off and see if there is any change in brightness.
If the backlights are out, you need to know if the set ever has video when they turn it on, or does it go out after they have had the set on for a period of time. If the set occasionally will not have backlights when it is first turned on, suspect the panel or power supply/IP board. If the set has video for a while and then loses the backlights, suspect a power supply/IP board or main board. Typically the panel will cause a no backlight at turn on, while the power supply and Main Board will cause the backlights to go out after a period of time. If the set has backlights when first turned on and the lights change their brightness in several steps before quickly going out, suspect the IP board.
If the backlights are on when the set loses video after it has been on for a while, most likely the LVDS cable is defective. If the set has backlights but no video when it is first turned on, the T/Con or Main Board would probably be at fault.
Always check the simple things first, like a LVDS cable that is not plugged in properly or a power connector to the panel being loose.
There are exceptions to every rule, but this generally should help with narrowing down no video in LCD sets.
Samsung LE40R76B LCD TV
Symptom: Some vertical lines on the TV screen. But sound is ok.
> Check the PSU output voltages all ok. After that checking their T-con board Vcc input and Voltage regulator IC. Found that 2.5V Voltage Regulator IC no output. After replaced it the TV screen is ok.
Samsung UNxxC9000 LED TV
Symptom: The UNxxC9000 LED TV power up sequence
This power up sequence can help you troubleshoot the UNxxC9000, here is the power up:
a. When the AC cord is plugged in, the voltage on the STBY pin goes to 5.3V.
b. The MCU (Microcontroller, Micon &etc) on the mainboard actively looks for the user to press Power On switch from remote control or the TV itself.
c. When a user presses Power, the MCU sends a “High” voltage (0-1.2V transition) to the SMPS/PSU via Power_On/Off pin to activate the rest of the voltages.
d. After the 0-1.2V transition on the POWER_On/Off pin, the following voltages are activated on CNM801 and the “Melody” plays.
- Vamp= 18VDC
- OD_On/Off= 3.3V
- D5.3V = 5V
- D12V = 13V
e) Approximately two seconds later, 5V is applied to the BLU_On/Off pin.
f) Once the BLU_On/Off pin is activated, the LED arrays turn on. CNL801 supplies high voltage to the LED arrays. The following voltages are activated on CNL801 (with respect to chassis GND):
- BOT1+ = 170VDC
- BOT1- = 45VDC
- TOP1- = 45VDC
- TOP1+ = 170VDC
- TOP2+ = 170VDC
- TOP2- = 45VDC
- BOT2- = 45VDC
- BOT2+ = 170VDC
g) High voltage is applied to the panel LED arrays though connectors CN401 and CN402: Pin 1 and 12
-Approximately 170VDC (when referenced to the chassis GND).
-Voltage varies when referenced to connector GND.
Pin 6 and 7
-GND (effective).
-Approximately 45VDC when the backlight is lowest.
-GND Pins
-GND Potential is highest when signal is >90% duty cycle (almost DC).
-GND Potential is lowest when signal is <10% duty cycle (almost GND).
-Level is controlled by the mainboard though the Bot_Dim and Top_Dim pins on connector CNM801
Model: Samsung LN19C350DXZA LCD TV
Symptom: Display is completely Green color only.
> LVDS cable not properly inserted or dirty in the contact pins. Clean the LVDS cable contact pins and connect it back properly.
Samsung UN46C6300SF LED TV
Symptom: No Power
> This ICB801 (ICE3BR1765J) Power IC is defective on the PSU board.
Samsung LA32R91B LCD TV
Symptom: TV brightness and contrast features automatically change to 100% (maximum).
Even using the remote control adjusts it to 50%, but in a short time it will automatically change to 100% of brightness and contrast.
> Found some bulged electrolytic capacitors on the line of DC supply to mainboard. After replaced these electrolytic caps, the symptom was getting better but not completely. Even disconnect the front control panel and checking their circuit line till mainboard also normal. It is no any leakage ceramic caps in that circuit line. So it will suspect the flash memory, eeprom IC or the MCU. So starting from the easy way first, checking the eeprom IC. This eeprom IC is beneath of the mainboard and it is using 24C256BN (SMD SOP-8, 8 pins IC). Yes, this eeprom IC (AT24C256C) can be as a replacement for 24C256BN. After replaced a new blank EEPROM IC, the V problem solved.
Samsung LE27T51B LCD TV
Symptom: Dark frame with color stripes.
> Its looks like the unstable voltage problem. Check and replace UP4 (L1117DG) on T-CON board.
Samsung LE32R73BD LCD TV
Symptom: No picture and no OSD menu. Backlight OK.
> Reflow LVDS socket on screen driver PCB and mainboard PCB.
Samsung LE32R74BD LCD TV
Symptom: TV dead. Pulsating noise came from PSU and LED light flashes.
> Check schottky diode DM854 (MBRF1545CT) in PSU for short circuit.
Samsung LN32A330J1DXZA, LN32A330J1NXZA LCD TV
Symptom: The TV takes longer to power on than normal.
The TV takes longer to power on than normal. You may hear several clicks while the TV attempts to power on.
Cause: The electrolytic in the capacitors on the power supply board over time will dry out causing the power supply to shut down during its initial power on cycle.
Samsung LN40A650A1FXZA, LN46A650A1FXZA,
LN40A750R1FXZC, LN46A750R1FXZA, LN40A750R1FXZA LCD TV
Symptom: Unit tries to start with melody but cycles off and back on.
> If the unit tries to turn on and makes the start-up melody but then immediately shuts off and starts again, unplug the LVDS cable and apply power again. If the set stays on, replace the T-Con board.
Samsung LNT3242HX/XAA, LNS2651DX/XAA LCD TV
Symptom: Picture is lost; sound OK after MAIN PCB was replaced
> If you get the symptoms after replacing MAIN PCB and made all correct setups in "OPTION BYTE":
- Lost picture after 5-10 minutes but sound OK, picture comes back if you restart the TV but just to be lost again after the same interval or - Picture is lost intermittently every 10-20 sec. and comes back itself, again sound OK.
You may not have to come back with another Main PCB, this may be corrected just by moving the connection between inverter and SMPS on the SMPS board. If it was on A-CNM803 move it to S-CNM802 or vice versa from S-CNM802 to A-CNM803 on the SMPS board. If this is not working then use a new MAIN PCB. This may be applied to other LCD models too.
Samsung LNS4041DX/XAA LCD TV
Symptom: Unit Continually Cycling On and Off. Set turns on and off in a continuous cycle. Play the melody each time.
Repair/Solutions: First, check the power supply voltages, if missing, replace the power PCB. Next unplug the LVDS cable. If the set continues to cycle, replace the main PCB. If the cycling stops, replace the LCD panel. Part numbers are version dependent, so be sure to check the set's version.
Samsung LE32R73BD: No picture and NO OSD menu. Backlight OK.
Symptom: No picture and no OSD menu. Backlight OK.
> Reflow LVDS socket on screen driver PCB and main board PCB.
SAMSUNG LE32R74BD: TV dead.
Symptom: TV dead. Pulsating noise from PSU and LED light flashes.
> Check the shottky diode DM854 (MBRF1545CT) in PSU for short circuit.
Samsung LE27T51B: Dark frame with color stripes
Samsung LE27T51B LCD TV
Dark frame with color stripes.
> Unstable voltage problem. Check and replace UP4 (L1117DG) on T-CON board.
Samsung LN40A650_A750_LN46A750: Unit tries to start with melody but cycles off and back on Samsung LN40A650A1FXZA,LN46A650A1FXZA,LN40A750R1FXZC,LN46A 750R1FXZA,LN40A750R1FXZA LCD TV
Unit tries to start with melody but cycles off and back on
> If the unit tries to turn on and makes the startup melody but then immediately shuts off and starts again, unplug the LVDS cable and apply power again. If the set stays on, replace the T-Con board.
Samsung LNT4665FX/XAA lost brightness when you replaced MAIN PCB Samsung LNT4665FX/XAA LCD TV
LNT4665FX/XAA lost brightness when you replaced MAIN PCB
> Because MAIN PCB BN94-01199E is designed to work with both models LNT4665FX/XAA and LNT4661FX/XAA when you replaced the board is possible to lose the brightness. Go in SERVICE MODE and turn value LVDS BYTE from 8 to 10.
Samsung LNS4051: Dead Backlight Flashes On Then Off Samsung LNS4051DX/XAA LCD TVDEAD BACKLIGHT FLASHES ON THEN OFF
UNIT WOULD FLASH ON THEN OFF AND AUDIO WOULD WORK. YOU COULD SEE VIDEO WITH A FLASHLIGHT. SOMETIMES UNIT WOULD STAY ON AND RUN IF YOU CYCLED ON AND OFF MANY TIMES. FOUND BAD SOLDER CONNECTION ON IP BOARD TI801 ON PRIMARY SIDE. RESOLDERED AND CORRECTED PROBLEM.
Samsung most models: Flickering on the screen intermittently
Model/s: Samsung
LN32B360C5DXZA,LN32B530P7FXZA,LN32B460B2DXZA,LN32B 540P8DXZA,LN32B550K1FXZA,LN37B530P7FXZA,LN37B550K1FXZA,LN40B550K1FXZA,LN40B530P7FXZA,LN40B 530P7NXZA,LN40B530P7FXZC,LN40B540P8FXZA,
LN46B530P7NXZA,LN46B530P7FXZA,LN46B550K1FXZA,LN46B 540P8FXZA.Symptom: Flickering on the screen intermittently
When the unit is connected via HDMI to a Scientific Atlanta cable set top box set in by pass mode for resolutions 480p and 720p a flickering will occur.
> Change the cable box to a fixed resolution. OR Have the customer install the latest TV firmware which can be located on samsung.com.
Samsung most models: Unit cycles on/off during startup
Model/s: Samsung LN46A550P3FXZA,LN46A650A1FXZA,LN46A530P1FXZA,LN46A 750R1FXZA,LN46A860S2FXZA,LN46A950D1FXZA,LN46A540P2FXZA,LN46A850S1FXZA,LN46A630M1FXZA,LN46A 580P6FXZA,LN52A530P1FXZA,LN52A750R1FXZA,
LN52A650A1FXZA,LN52A550P3FXZA,LN52A630M1FXZA,LN52A860S2FXZA,LN52A850S1FXZA,LN52A540P2FXZA,LN40A530P1FXZA,LN40A450C1DXZA,LN40A330J1DXZA,LN40A 550P3FXZA,LN40A650A1FXZA,LN40A630M1FXZA,LN40A540P2FXZA LCD TV.
Unit cycles on/off during startup
> If the unit tries to turn on but begins to cycle on and off before any video is displayed and all of the SMPS voltages are good, disconnect the LVDS cable at the T-Con board. If the set starts and the backlights come on, replace the T-Con board. If the set does not start, disconnect the LVDS cable at the main board. If the set starts, replace the LVDS cable. If the set still does not startup, replace the main board.
Samsung LNS4051DX/XAA LCD TV
Symptom: Clicking repeatedly TV will not turn on
> Found 2 electrolytic 100uf at 16v capacitors on the 5v line C115 and C123 bad.
Or replace the power supply.
Samsung LNS4051DX/XAA LCD TV
Symptom: Dead Backlight Flashes On then Off.
UNIT WOULD FLASH ON THEN OFF AND AUDIO WOULD WORK. YOU COULD SEE VIDEO WITH A FLASHLIGHT. SOMETIMES UNIT WOULD STAY ON AND RUN IF YOU CYCLED ON AND OFF MANY TIMES. FOUND BAD SOLDER CONNECTION ON IP BOARD TI801 ON PRIMARY SIDE. RESOLDERED AND CORRECTED PROBLEM.
Samsung LNS4692DX/XAA LCD TV
Symptom: No video TV but has backlight and audio. TV will not come on.
> Found pico fuse open at cp1 on the T-CON PCB. If shorted CP1 with a wire jumper, TV comes on and runs fine. Replace the Pico fuse or T-CON PCB.
Samsung LNT3242HX/XAA, LNT3232HX/XAA LCD TV
Symptom: Can’t power on.
> TV would not come on. Removed the back and as soon as we did the set came on. Found glue was around cables on the SMPS. Cleaned glue off and cleaned the terminals. Set operates normally.
Samsung LNT3253HX/XAA LCD TV
Symptom: After a few minutes when TV warms-up picture becomes distorted
> 10-15 minutes after you turned on the unit panel warms-up and picture becomes distorted. If you just push the TV's frame picture becomes even more distorted. On the back of the panel the CONTROL ASIC area is very hot. Replace the panel to fix the problem.
Samsung LNT4065FX/XAA, LNT4665FX/XAA,
LNT5265FX/XAA, LNT4061FX/XAA, LNT4661FX/XAA LCD TV
Symptom: Blue screen without signal. If provide with signal the blue screen
will flash white short horizontal lines.
> Refit or replace LVDS cable, check if the cable not strangled by the metal cover and loosen up the screws of the cover.
Samsung LN32B360C5DXZA,LN32B530P7FXZA,LN32B650T1FXZA,LN32B460B2DXZA,LN32B540P8DXZA,LN32B550K1FXZA,LN32B640R3FXZA,LN32B457C6HXZA,LN32B450C4HXZA,LN37B457C6HXZA,LN37B530P7FXZA,LN37B650T1FXZA,LN37B550K1FXZA,LN40B457C6HXZA,LN40B550K1HXZA,LN40B 500P3FXZA,LN40B550K1FXZA,LN40B650T1FXZA,LN40B530P7FXZA,LN40B530P7NXZA,LN40B750U1FXZA,LN40B 540P8FXZA,LN40B610A5FXZA,LN40B630N1FXZA,
LN40B640R3FXZA,LN46B650T1FXZA,LN46B530P7NXZA,LN46B530P7FXZA,LN46B550K1FXZA,LN46B610A5FXZA,LN46B540P8FXZA,LN46B630N1FXZA,LN46B640R3FXZA,LN46B 750U1FXZA,LN52B550K1HXZA,LN52B610A5FXZA,LN52B550K1FXZA,LN52B540P8FXZA,LN52B530P7FXZA,LN52B630N1FXZA,LN52B750U1FXZA,LN55B640R3FXZA,LN55B650T1FXZA LCD TV
Symptom: Firmware blinking in Red at the top of the screen
Problem - After changing the main board, I'm now stuck with the firmware blinking in RED print at the top of the screen.
> The unit is stuck in aging mode. To exit, simply hit the menu button on the TV itself.
Samsung LN32B360C5DXZA,LN32B530P7FXZA,LN32B460B2DXZA,LN32B540P8DXZA,LN32B550K1FXZA,LN37B530P7FXZA,LN37B550K1FXZA,LN40B550K1FXZA,LN40B530P7FXZA,LN40B 530P7NXZA,LN40B530P7FXZC,LN40B540P8FXZA,LN46B530P7NXZA,LN46B530P7FXZA,LN46B550K1FXZA,LN46B 540P8FXZA
Samsung LN26B460B2DXZA; LN26B360C5DXZA; LN26B457C6HXZA; LN32B460B2DXZA; LN32B360C5DXZA; LN32B540P8DXZA; LN32B457C6HXZA;LN32B530P7FXZA;LN32B550K1FXZA; LN37B530P7FXZA; LN37B550K1FXZA;LN37B650T1FXZA
Symptom: No Backlight but sound ok.
TV will power up but have no backlight operation (No display). Sound is OK.
Procedure:
1. Verify that the TV is within the serial number range by checking the ninth digit in the serial number (i.e. AZ4D3CTS5 Ninth digit is a 5).
2. If the digit is 4 or 5, check the number on the diode itself to verify whether it has already been replaced.
3. If the diode has “0907”, “0908” or “0909” on its case (refer to photos 1 & 2), replace with new (Part number 0402-001415).
Verify the cause of the symptom by measuring (in circuit) across the diode (location DP805) (see photos 3 through 6). If the resistance measures between 500 and 600 ohms, the diode is good and therefore the symptom is being caused by a different reason. If the resistance measurement approaches zero ohms (shorted) the diode is defective and needs to be replaced using part number 0402-001415.
> There are two versions of the IP board with different physical layouts using the same diode type. Replace the diode using standard soldering methods for a lead-free application. If the diode is not available, order the IP Board
This is one of the panels that are mounted upside down, so the stand mounts just below and behind the panel frame. Any slight pressure from the stand can cause the frame to make contact. In many cases, the TV can be slightly flexed to make this issue occur.
You may see besides a T-Con ribbon cable that the sub-board is not seated properly, and is in fact bowing towards the outer frame. Pulling the frame out slightly, you can see one of the SMD capacitors that can make connection with the frame. Adding felt to the affected area will solve the issue.
Samsung most model: Firmware Blinking in Red at the Top of the Screen
Model/s: Samsung LN32B360C5DXZA,LN32B530P7FXZA,LN32B650T1FXZA,LN32B 460B2DXZA,LN32B540P8DXZA,LN32B550K1FXZA,LN32B640R3FXZA,LN32B457C6HXZA,LN32B450C4HXZA,LN37B 457C6HXZA,LN37B530P7FXZA,LN37B650T1FXZA,
LN37B550K1FXZA,LN40B457C6HXZA,LN40B550K1HXZA,LN40B500P3FXZA,LN40B550K1FXZA,LN40B650T1FXZA,LN40B530P7FXZA,LN40B530P7NXZA,LN40B750U1FXZA,LN40B 540P8FXZA,LN40B610A5FXZA,LN40B630N1FXZA,LN40B640R3FXZA,LN46B650T1FXZA,LN46B530P7NXZA,LN46B 530P7FXZA,LN46B550K1FXZA,LN46B610A5FXZA,
LN46B540P8FXZA,LN46B630N1FXZA,LN46B640R3FXZA,LN46B750U1FXZA,LN52B550K1HXZA,LN52B610A5FXZA,LN52B550K1FXZA,LN52B540P8FXZA,LN52B530P7FXZA,LN52B 630N1FXZA,LN52B750U1FXZA,LN55B640R3FXZA,LN55B650T1FXZA LCD TV.
Firmware blinking in Red at the top of the screen.
> Problem - After changing the main board, I'm now stuck with the firmware text info blinking in RED print at the top of the screen. The unit is stuck in aging mode. To exit, simply hit the menu button on the TV itself.
Samsung LNT4065_LNT5265: With Signal-Blue Screen and Flashing White Short Horizontal Lines
Model/s: LNT4065FX/XAA,LNT4665FX/XAA,LNT5265FX/XAA,LNT4061FX/XAA,LNT4661FX/XAA
Blue screen without signal, with signal -blue screen with flashing white short horizontal lines
> Refit or replace LVDS cable, check if the cable not strangled by the metal cover and loosen up the screws of the cover.
Samsung LNT3242_3232 : Wont Power On
Samsung LNT3242HX/XAA,LNT3232HX/XAA LCD TV
Symptom: Wont power on
TV would not come on. Removed the back and as soon as we did the set came on.
Found glue all on the cables to the smps. Cleaned glue off and cleaned the terminals. Set operates normally.
Samsung LN32A330: The TV takes longer to power on than normal
Samsung LN32A330J1DXZA,LN32A330J1NXZA LCD TV
The TV takes longer to power on than normal
The TV takes longer to power on than normal. You may hear several clicks while the TV attempts to power on.
The electrolytic in the capacitors on the power supply board over time will dry out causing the power supply to shut down during its initial power on cycle.
Samsung: Unit tries to start with melody but cycles off and back on
Samsung LN40A650A1FXZA,LN46A650A1FXZA,LN40A750R1FXZC,LN46A 750R1FXZA,LN40A750R1FXZA LCD TV
Unit tries to start with melody but cycles off and back on
> If the unit tries to turn on and makes the startup melody but then immediately shuts off and starts again, unplug the LVDS cable and apply power again. If the set stays on, replace the T-Con board.
Samsung: Will not turn on, cycles on and off with startup melody, no backlights
Samsung LN52A650A1FXZA,LN40A650A1FXZA,LN46A650A1FXZA,LN52A 650A1FXZC,LN46A650A1FXZC LCD TV
Will not turn on, cycles on and off with startup melody, no backlights
> If the set will try to turn on and the startup melody sounds but no backlight appears and the set cycles off and on every 5 to 10 seconds, unplug the LVDS cable from the T-Con/FRC board. If the set then runs and the backlights come on and stay on, replace the defective T-Con/FRC board.
Samsung LNS4692: No video TV, has backlight and audio. TV will not come on
Samsung LNS4692DX/XAA LCD TV
No video TV, has backlight and audio. TV will not come on.
> Found pico fuse open at cp1 on the T-CON PCB short cp1 TV comes on runs fine. Replace the T-CON PCB.
Samsung: Standby light is on, flashes once briefly then unit attempts to turn on
Samsung LN32A330J1DXZA,LN32A450C1DXZA,LN32A550P3FXZA,LN32A 540P2DXZA,LN32A330J1NXZA,LN32A450C1HXZA,LN32A450C3 HXZA, LN32A300J1DXZA LCD TV
Standby light is on, flashes once briefly then unit attempts to turn on
If the unit will not turn on, but the red standby LED is on and flashes once quickly when the power button is pressed on the remote or the TV, the 2200uf 10v filter capacitor on the SMPS has failed. This capacitor is located in the upper right side of the power supply close to the cable that connects the main board. Visual inspection will normally show that it has a swollen top. Replace capacitor and inspect the others in the filter stage to restore operation.
Samsung: Unit cycles on and off several times before starting
LNT4069FX/XAA,LNT4066FX/XAA,LNT4669FX/XAA,LNT4071FX/XAA,LNT4671FX/XAA,LNT5271FX/XAA,LNT4065FX/XAA,LNT4665FX/XAA,LNT5265FX/XAA,LNT4061FX/XAA,LNT4661FX/XAA
Unit cycles on and off several times before starting
> If the unit will cycle on and off several times before turning on and then playing fine, check the power supply carefully for filter capacitors with bulged tops. Replace the capacitors or power supply to correct the issue.
Samsung: Auto-shutdown on 2008 LCD TV’s
Samsung LN32A330J1DXZA,LN32A450C1DXZA,LN32A650A1FXZA,LN32A 550P3FXZA,LN32A540P2DXZA,LN32A330J1NXZA,LN32A300J1 DXZA, LN40A530P1FXZA, LN40A450C1DXZA, LN40A750R1FXZA, LN40A330J1DXZA, LN40A550P3FXZA, LN40A540P2FXZA, LN40A500T1FXZA, LN46A530P1FXZA, LN46A860S2FXZA, LN46A750R1FXZA, LN46A550P3FXZA, LN46A650A1FXZA, LN46A950D1FXZA, LN46A540P2FXZA, LN46A500T1FXZA, LN46A850S1FXZA, LN46A630M1FXZA, LN46A850S1FXZX, LN46A580P6FXZA, LN52A530P1FXZA, LN52A750R1FXZA, LN52A650A1FXZA, LN52A550P3FXZA, LN52A630M1FXZA, LN52A860S2FXZA, LN52A850S1FXZA, LN52A540P2FXZA, LN52A580P6FXZA.
Auto-shutdown on 2008 LCD TV’s.
> Upon inspections of 2008 LCD TV's we have found that the LVDS (ribbon cable) can cause an auto shut down. Even if the LVDS cable doesn’t look defective try changing it anyway and retest the TV. It is a good practice to carry a few extra LVDS cables in your van for such testing circumstances.
Samsung: Unit tries to start with melody but cycles off and back on
Samsung LN40A650A1FXZA,LN46A650A1FXZA,LN40A750R1FXZC,LN46A 750R1FXZA,LN40A750R1FXZA LCD TV
Unit tries to start with melody but cycles off and back on.
> If the unit tries to turn on and makes the startup melody but then immediately shuts off and starts again, unplug the LVDS cable and apply power again. If the set stays on, replace the T-Con board.
Samsung LNS2651 & LNT3242: Picture is lost, sound OK after MAIN PCB was replaced
Samsung LNT3242HX/XAA, LNS2651DX/XAA LCD TV
Picture is lost, sound OK after MAIN PCB was replaced
> If after replacing MAIN PCB and made all correct setups in "OPTION BYTE" you get the symptoms:
* lost picture after 5-10 min. but sound OK, picture comes back if you restart the LCD but just to be lost again after the same interval or
* Picture is lost intermittently every 10-20 sec. and comes back itself, again sound OK.
You may not have to come back with another Main PCB, this may be corrected just by moving the connection between inverter and SMPS on the SMPS board. If it was on A-CNM803 move it to S-CNM802 or vice versa from S-CNM802 to A-CNM803 on the SMPS board, see picture. If this is not working then use a new MAIN PCB.
This may be applied to other LCD models too.
Samsung LNS4051: Clicking repeatedly TV will not turn on
Samsung LNS4051DX/XAA LCD TV
Clicking repeatedly TV will not turn on
> Found 2 electrolytic 100uf at 16v capacitors on the 5V line C115 and C123 bad. Or replace the power supply.
Samsung: Backlight Failure Testing
Model/s: Samsung LN32B360C5DXZA,LN32B530P7FXZA,LN32B650T1FXZA,LN32B 460B2DXZA,LN32B540P8DXZA,LN32B550K1FXZA,LN32B640R3 FXZA, LN32B457C6HXZA, LN32B450C4HXZA, LN32B540P8DUZA, LN32B450C3HXZA, LN32B460B2DUZA, LN32B360C5DUZA, LN32B550K1FUZA, LN32B530P7FUZA, LN32B450C3HUZA, LN40B530P7FUZA, LN40B550K1FUZA, LN40B457C6HXZA, LN40B550K1HXZA, LN40B610A5FUZA, LN40B640R3FUZA, LN40B650T1FUZA, LN40B630N1FUZA, LN40B540P8FUZA, LN40B500P3FXZA, LN40B550K1FXZA, LN40B650T1FXZA, LN40B530P7FXZA, LN40B530P7NXZA, LN40B750U1FXZA, LN40B540P8FXZA, LN40B630N1FXZA, LN40B640R3FXZA, LN52B550K1HXZA, LN52B610A5FXZA, LN52B550K1FXZA, LN52B540P8FXZA, LN52B530P7FXZA, LN52B630N1FXZA, LN52B750U1FXZA LCD TVs.
Backlight Failure Testing
> Backlight failures can be partial or full failure Check the backlight supply voltage (refer to service manual) If supply voltage is present, use a flashlight behind the television and shine a light through the panel. If the video is working you will see it.
Samsung LNS4041: Unit Continually Cycling On and Off
Samsung LNS4041DX/XAA LCD TV
Unit Continually Cycling On and Off. Set turns on and off in a continuous cycle. Plays the melody each time.
> First, check the power supply voltages, if missing, replace the power PCB. Next unplug the LVDS cable. If the set continues to cycle, replace the main PCB. If the cycling stops, replace the LCD panel. Part numbers are version dependent, so be sure to check the set's version.
Samsung LNT4671 & LNT5271: TV is cycling, the red led blinking and the relay is cycling
Samsung LNT5271FX/XAA,LNT4671FX/XAA LCD TV
TV is cycling, the red led blinking and the relay is cycling sometime TV will come on.
> TV is cycling, the red led blinking and the relay is cycling sometime TV will come on. The Main board replaced, did not fix. This unit was a Refurb, found cable from the main board to the side AV jack was reversed, is not labeled as to direction of use. This cable if reversed will be hot to the touch. Found by removing and replugging and changing direction of cable TV worked. This was tried on both model numbers with the same result.
Samsung: DEAD BACKLIGHT FLASHES ON THEN OFF
Model/s: Samsung LNS4051DX/XAA LCD TV
Symptom: Dead backlight flashes on then off.
UNIT WOULD FLASH ON THEN OFF AND AUDIO WOULD WORK. YOU COULD SEE VIDEO WITH A FLASHLIGHT. SOMETIMES UNIT WOULD STAY ON AND RUN IF YOU CYCLED ON AND OFF MANY TIMES. FOUND BAD SOLDER CONNECTION ON IP BOARD TI801 ON PRIMARY SIDE. RESOLDERED AND CORRECTED PROBLEM.
Samsung: Poor or Intermittent Video
Model/s: Samsung LNS4695DX/XAA,LNS4696DX/XAA,LNS4096DX/XAA,LNS4095DX/XAA LCD TV
Symptom: Poor or Intermittent Video
Cure/Solutions: Check the LVDS cable where it connects to the panel interface board. Be sure that the cable does not have any glue on it. On occasion, the glue can cause a poor connection if it gets into the connector. Remove glue or replace the LVDS cable with BN39-00726A.
Samsung: Half the screen is purple
Model/s: Samsung LNT4065FX/XAA,LNT4665FX/XAA,LNT5265FX/XAA,LNT4061FX/XAA,LNT4661FX/XAA LCD TV
Symptom: Half screen is purple
Cure/Solutions: Half screen is purple. LCD panel controller board is defective. Panel needs to be replaced.
Samsung: Video Stuttering or Hesitation
Model/s: Samsung LNT4071FX/XAA,LNT4671FX/XAA,LNT5271FX/XAA LCD TV
Symptom: Video Stuttering or Hesitation
Cure/Solutions: The customer may complain that the video has a stutter or hesitation when viewing regular programming, either standard definition or high definition.
To fix, go into the customer menu, select Picture, then scroll to Auto Motion Plus 120Hz and select Off.
This enhancement circuit works for some movies, but can introduce severe hesitations and ghosting on regular programming. The customer should also be informed that this does not affect the 120Hz operation of the panel. The panel operates at 120Hz regardless of this setting.
Samsung: Troubleshooting Inverter PCB boards
Model/s: Samsung LNT4061FX/XAA, LN32A450C1DXZC, LN32A550P3FXZC, LN32A550P3FXZX, LN32A450C1DXZX,
LN32A650A1FXZA, LN32A450C1XZD, LN32A450C1DXZA, LN32A540P2DXZA, LN32A450C1XZP, LN32A550P3RXZD, LN40A530P1FXZA, LN40A530P1FXZX, LN40A450C1HXZX, LN40A450C1DXZA, N40A750R1FXZA, LN40A450C1DXZX, LN40A530P1FXZC, LN40A550P3FXZC, LN40A650A1FXZC, LN40A550P3FXZX, LN40A750R1FXZC, LN40A330J1DXZX, LN40A650A1FXZX, LN40A450C1XZD, N40A450C1DXZC, LN40A330J1DXZA, LN40A550P3FXZA, LN40A650A1FXZA, LN40A750R1FXZX, LN40A550P3RXZD, LN40A330J1XZD, LN40A630M1FXZA, LN40A540P2FXZA, LN40A650A2RXZD,
LN40A630M1FXZC, LN40A630M1FXZX, LN40A610A3RXZD, LN40A500T1FXZA, LN40A330J1XZP, LN40A450C1XZP, LN40A650A1RXZP, LN40A610A1RXZD, LN40A650A1FXZD LCD TVs.
Troubleshooting Inverter PCB boards
The inverter PCB is the power supply for the Cold Cathode Fluorescent tubes. The inverter acts exactly like the ballast used in a standard fluorescent light fixture. In the case of an LCD TV, 24 volts from the power supply is applied to a switch mode power supply (SMPS). The SMPS outputs ~1000 Volts to energize the bulbs then the voltage drops to ~ 500 volts for run operation. The SMPS switching frequency is around 90 KHz. The first step for verifying inverter board operation is to confirm the 24 volt supply is present. An oscilloscope can also be used to verify the SMPS circuit is oscillating. Simply holding the oscilloscope probe in the area of the switching transformer will show screen activity if the switching action is taking place. Measuring the SMPS output with standard equipment is not recommended as this is high voltage and at a high frequency.
Samsung: Intermittent LCD Video Troubleshooting
Model/s: Samsung LNT4069FX/XAA, LNT4066FX/XAA, LNT4669FX/XAA, LNT3255HTX/XAA, LNT375HAX/XAA, LNT4042HX/XAA, LNT325HAX/XAA, LNT405HAX/XAA, LNT2353HTX/XAA, LNT3753HX/XAA, LNT2653HTX/XAA, LNT3242HTX/XAA, LNT3253HTX/XAA, LNT4042HTX/XAA, LNT4053HTX/XAA, LNT4071FX/XAA, LNT4671FX/XAA, LNT5271FX/XAA, LNT4642HX/XAA, LNT466FX/XAA, LNT4065FX/XAA, LNT4665FX/XAA, LNT5265FX/XAA, LNT2632HX/XAA, LNT2642HX/XAA, LNT2653HX/XAA, LNT3232HX/XAA, LNT3242HX/XAA, LNT3253HX/XAA, LNT3732HX/XAA, LNT4032HX/XAA, LNT4053HX/XAA, LNT4061FX/XAA, LNT4661FX/XAA LCD TVs.
Symptom: Intermittent LCD Video Troubleshooting
Troubleshooting intermittent video problems can be time consuming, but these tips may help narrow down the cause of an intermittent video problem.
The very first thing to do is to make sure the customer does not have OSD. They can verify this by just pressing Menu or Volume on their TV remote control. If they do have OSD, then the problem is most likely in the source and not the TV.
The next step when encountering an intermittent video problem is to find out if the backlights are on when the set loses video. You can probably obtain this information from the customer before you schedule the call. Ask if they noticed if the screen is completely black or if it is lit up slightly when the video goes out. They may be able to notice it better if they stand at an angle to the TV and turn it on or off and see if there is any change in brightness.
If the backlights are out, you need to know if the set ever has video when they turn it on, or does it go out after they have had the set on for a period of time. If the set occasionally will not have backlights when it is first turned on, suspect the panel or power supply/IP board. If the set has video for a while and then loses the backlights, suspect a power supply/IP board or main board. Typically the panel will cause a no backlight at turn on, while the power supply and Main Board will cause the backlights to go out after a period of time. If the set has backlights when first turned on and the lights change their brightness in several steps before quickly going out, suspect the IP board.
If the backlights are on when the set loses video after it has been on for a while, most likely the LVDS cable is defective. If the set has backlights but no video when it is first turned on, the T/Con or Main Board would probably be at fault.
Always check the simple things first, like a LVDS cable that is not plugged in properly or a power connector to the panel being loose.
There are exceptions to every rule, but this generally should help with narrowing down no video in LCD sets.
Samsung LE40R76B LCD TV
Symptom: Some vertical lines on the TV screen. But sound is ok.
> Check the PSU output voltages all ok. After that checking their T-con board Vcc input and Voltage regulator IC. Found that 2.5V Voltage Regulator IC no output. After replaced it the TV screen is ok.
Samsung UNxxC9000 LED TV
Symptom: The UNxxC9000 LED TV power up sequence
This power up sequence can help you troubleshoot the UNxxC9000, here is the power up:
a. When the AC cord is plugged in, the voltage on the STBY pin goes to 5.3V.
b. The MCU (Microcontroller, Micon &etc) on the mainboard actively looks for the user to press Power On switch from remote control or the TV itself.
c. When a user presses Power, the MCU sends a “High” voltage (0-1.2V transition) to the SMPS/PSU via Power_On/Off pin to activate the rest of the voltages.
d. After the 0-1.2V transition on the POWER_On/Off pin, the following voltages are activated on CNM801 and the “Melody” plays.
- Vamp= 18VDC
- OD_On/Off= 3.3V
- D5.3V = 5V
- D12V = 13V
e) Approximately two seconds later, 5V is applied to the BLU_On/Off pin.
f) Once the BLU_On/Off pin is activated, the LED arrays turn on. CNL801 supplies high voltage to the LED arrays. The following voltages are activated on CNL801 (with respect to chassis GND):
- BOT1+ = 170VDC
- BOT1- = 45VDC
- TOP1- = 45VDC
- TOP1+ = 170VDC
- TOP2+ = 170VDC
- TOP2- = 45VDC
- BOT2- = 45VDC
- BOT2+ = 170VDC
g) High voltage is applied to the panel LED arrays though connectors CN401 and CN402: Pin 1 and 12
-Approximately 170VDC (when referenced to the chassis GND).
-Voltage varies when referenced to connector GND.
Pin 6 and 7
-GND (effective).
-Approximately 45VDC when the backlight is lowest.
-GND Pins
-GND Potential is highest when signal is >90% duty cycle (almost DC).
-GND Potential is lowest when signal is <10% duty cycle (almost GND).
-Level is controlled by the mainboard though the Bot_Dim and Top_Dim pins on connector CNM801
Model: Samsung LN19C350DXZA LCD TV
Symptom: Display is completely Green color only.
> LVDS cable not properly inserted or dirty in the contact pins. Clean the LVDS cable contact pins and connect it back properly.
Samsung UN46C6300SF LED TV
Symptom: No Power
> This ICB801 (ICE3BR1765J) Power IC is defective on the PSU board.
Samsung LA32R91B LCD TV
Symptom: TV brightness and contrast features automatically change to 100% (maximum).
Even using the remote control adjusts it to 50%, but in a short time it will automatically change to 100% of brightness and contrast.
> Found some bulged electrolytic capacitors on the line of DC supply to mainboard. After replaced these electrolytic caps, the symptom was getting better but not completely. Even disconnect the front control panel and checking their circuit line till mainboard also normal. It is no any leakage ceramic caps in that circuit line. So it will suspect the flash memory, eeprom IC or the MCU. So starting from the easy way first, checking the eeprom IC. This eeprom IC is beneath of the mainboard and it is using 24C256BN (SMD SOP-8, 8 pins IC). Yes, this eeprom IC (AT24C256C) can be as a replacement for 24C256BN. After replaced a new blank EEPROM IC, the V problem solved.
Samsung LE27T51B LCD TV
Symptom: Dark frame with color stripes.
> Its looks like the unstable voltage problem. Check and replace UP4 (L1117DG) on T-CON board.
Samsung LE32R73BD LCD TV
Symptom: No picture and no OSD menu. Backlight OK.
> Reflow LVDS socket on screen driver PCB and mainboard PCB.
Samsung LE32R74BD LCD TV
Symptom: TV dead. Pulsating noise came from PSU and LED light flashes.
> Check schottky diode DM854 (MBRF1545CT) in PSU for short circuit.
Samsung LN32A330J1DXZA, LN32A330J1NXZA LCD TV
Symptom: The TV takes longer to power on than normal.
The TV takes longer to power on than normal. You may hear several clicks while the TV attempts to power on.
Cause: The electrolytic in the capacitors on the power supply board over time will dry out causing the power supply to shut down during its initial power on cycle.
Samsung LN40A650A1FXZA, LN46A650A1FXZA,
LN40A750R1FXZC, LN46A750R1FXZA, LN40A750R1FXZA LCD TV
Symptom: Unit tries to start with melody but cycles off and back on.
> If the unit tries to turn on and makes the start-up melody but then immediately shuts off and starts again, unplug the LVDS cable and apply power again. If the set stays on, replace the T-Con board.
Samsung LNT3242HX/XAA, LNS2651DX/XAA LCD TV
Symptom: Picture is lost; sound OK after MAIN PCB was replaced
> If you get the symptoms after replacing MAIN PCB and made all correct setups in "OPTION BYTE":
- Lost picture after 5-10 minutes but sound OK, picture comes back if you restart the TV but just to be lost again after the same interval or - Picture is lost intermittently every 10-20 sec. and comes back itself, again sound OK.
You may not have to come back with another Main PCB, this may be corrected just by moving the connection between inverter and SMPS on the SMPS board. If it was on A-CNM803 move it to S-CNM802 or vice versa from S-CNM802 to A-CNM803 on the SMPS board. If this is not working then use a new MAIN PCB. This may be applied to other LCD models too.
Samsung LNS4041DX/XAA LCD TV
Symptom: Unit Continually Cycling On and Off. Set turns on and off in a continuous cycle. Play the melody each time.
Repair/Solutions: First, check the power supply voltages, if missing, replace the power PCB. Next unplug the LVDS cable. If the set continues to cycle, replace the main PCB. If the cycling stops, replace the LCD panel. Part numbers are version dependent, so be sure to check the set's version.
Samsung LE32R73BD: No picture and NO OSD menu. Backlight OK.
Symptom: No picture and no OSD menu. Backlight OK.
> Reflow LVDS socket on screen driver PCB and main board PCB.
SAMSUNG LE32R74BD: TV dead.
Symptom: TV dead. Pulsating noise from PSU and LED light flashes.
> Check the shottky diode DM854 (MBRF1545CT) in PSU for short circuit.
Samsung LE27T51B: Dark frame with color stripes
Samsung LE27T51B LCD TV
Dark frame with color stripes.
> Unstable voltage problem. Check and replace UP4 (L1117DG) on T-CON board.
Samsung LN40A650_A750_LN46A750: Unit tries to start with melody but cycles off and back on Samsung LN40A650A1FXZA,LN46A650A1FXZA,LN40A750R1FXZC,LN46A 750R1FXZA,LN40A750R1FXZA LCD TV
Unit tries to start with melody but cycles off and back on
> If the unit tries to turn on and makes the startup melody but then immediately shuts off and starts again, unplug the LVDS cable and apply power again. If the set stays on, replace the T-Con board.
Samsung LNT4665FX/XAA lost brightness when you replaced MAIN PCB Samsung LNT4665FX/XAA LCD TV
LNT4665FX/XAA lost brightness when you replaced MAIN PCB
> Because MAIN PCB BN94-01199E is designed to work with both models LNT4665FX/XAA and LNT4661FX/XAA when you replaced the board is possible to lose the brightness. Go in SERVICE MODE and turn value LVDS BYTE from 8 to 10.
Samsung LNS4051: Dead Backlight Flashes On Then Off Samsung LNS4051DX/XAA LCD TVDEAD BACKLIGHT FLASHES ON THEN OFF
UNIT WOULD FLASH ON THEN OFF AND AUDIO WOULD WORK. YOU COULD SEE VIDEO WITH A FLASHLIGHT. SOMETIMES UNIT WOULD STAY ON AND RUN IF YOU CYCLED ON AND OFF MANY TIMES. FOUND BAD SOLDER CONNECTION ON IP BOARD TI801 ON PRIMARY SIDE. RESOLDERED AND CORRECTED PROBLEM.
Samsung most models: Flickering on the screen intermittently
Model/s: Samsung
LN32B360C5DXZA,LN32B530P7FXZA,LN32B460B2DXZA,LN32B 540P8DXZA,LN32B550K1FXZA,LN37B530P7FXZA,LN37B550K1FXZA,LN40B550K1FXZA,LN40B530P7FXZA,LN40B 530P7NXZA,LN40B530P7FXZC,LN40B540P8FXZA,
LN46B530P7NXZA,LN46B530P7FXZA,LN46B550K1FXZA,LN46B 540P8FXZA.Symptom: Flickering on the screen intermittently
When the unit is connected via HDMI to a Scientific Atlanta cable set top box set in by pass mode for resolutions 480p and 720p a flickering will occur.
> Change the cable box to a fixed resolution. OR Have the customer install the latest TV firmware which can be located on samsung.com.
Samsung most models: Unit cycles on/off during startup
Model/s: Samsung LN46A550P3FXZA,LN46A650A1FXZA,LN46A530P1FXZA,LN46A 750R1FXZA,LN46A860S2FXZA,LN46A950D1FXZA,LN46A540P2FXZA,LN46A850S1FXZA,LN46A630M1FXZA,LN46A 580P6FXZA,LN52A530P1FXZA,LN52A750R1FXZA,
LN52A650A1FXZA,LN52A550P3FXZA,LN52A630M1FXZA,LN52A860S2FXZA,LN52A850S1FXZA,LN52A540P2FXZA,LN40A530P1FXZA,LN40A450C1DXZA,LN40A330J1DXZA,LN40A 550P3FXZA,LN40A650A1FXZA,LN40A630M1FXZA,LN40A540P2FXZA LCD TV.
Unit cycles on/off during startup
> If the unit tries to turn on but begins to cycle on and off before any video is displayed and all of the SMPS voltages are good, disconnect the LVDS cable at the T-Con board. If the set starts and the backlights come on, replace the T-Con board. If the set does not start, disconnect the LVDS cable at the main board. If the set starts, replace the LVDS cable. If the set still does not startup, replace the main board.
Samsung LCD TV service tips - 2
Samsung 32 Inches LCD TV
Symptom: Hissing or Hum noise of the SMPS in 32 inches LCD TV
There may be a sort of hissing noise in the SMPS for 32" LCD TV. The noise occurs when the set is in the stand by condition. The SMPS code is BN96- 03057A and defective SMPS version is the "REV 1.1".
> Replace the SMPS to new version (V1.2 or latest version).
Samsung 26, 32 & 37 Inches LCD TV Year 2009 Europe models
Symptom: No Power, No picture or no backlight.
Cause: DP805 Diode (MUR360).
> Change DP805 from MUR360 to 31GF6 diode on IP boards.
=> MUR360 risk range: 0907*/0908*/0909* marked on diode.
1. Change MUR360 Diode to 31GF6 Diode
2. Marking a dot on yellow box after changing this diode.
Symptom: Hissing or Hum noise of the SMPS in 32 inches LCD TV
There may be a sort of hissing noise in the SMPS for 32" LCD TV. The noise occurs when the set is in the stand by condition. The SMPS code is BN96- 03057A and defective SMPS version is the "REV 1.1".
> Replace the SMPS to new version (V1.2 or latest version).
Samsung 26, 32 & 37 Inches LCD TV Year 2009 Europe models
Symptom: No Power, No picture or no backlight.
Cause: DP805 Diode (MUR360).
> Change DP805 from MUR360 to 31GF6 diode on IP boards.
=> MUR360 risk range: 0907*/0908*/0909* marked on diode.
1. Change MUR360 Diode to 31GF6 Diode
2. Marking a dot on yellow box after changing this diode.
Samsung LNS4695DX/XAA, LNS4696DX/XAA,LNS4096DX/XAA,
LNS4095DX/XAA LCD TV
Symptom: Poor or Intermittent Video.
> Check the LVDS cable where it connects to the panel interface board. Be sure that the cable does not have any glue on it. On occasion, the glue can cause a poor connection if it gets into the connector. Remove glue or replace the LVDS cable with BN39-00726A.
Samsung LN32A330J1DXZA, LN32A450C1DXZA,LN32A550P3FXZA, LN32A540P2DXZA, LN32A330J1NXZA,LN32A450C1HXZA, LN32A450C3HXZA,LN32A300J1DXZA LCD TV
Symptom: Standby light is on, flashes once briefly then unit attempts to turn on
> If the unit will not turn on, but the red standby LED is on and flashes once quickly when the power button is pressed on the remote or the TV, the 2200uf 10v filter capacitor on the SMPS has failed. This capacitor is located in the upper right side of the power supply close to the cable that connects the main board. Visual inspection will normally show that it has a swollen top. Replace capacitor and inspect the others in the filter stage to restore operation.
Symptom: Poor or Intermittent Video.
> Check the LVDS cable where it connects to the panel interface board. Be sure that the cable does not have any glue on it. On occasion, the glue can cause a poor connection if it gets into the connector. Remove glue or replace the LVDS cable with BN39-00726A.
Samsung LN32A330J1DXZA, LN32A450C1DXZA,LN32A550P3FXZA, LN32A540P2DXZA, LN32A330J1NXZA,LN32A450C1HXZA, LN32A450C3HXZA,LN32A300J1DXZA LCD TV
Symptom: Standby light is on, flashes once briefly then unit attempts to turn on
> If the unit will not turn on, but the red standby LED is on and flashes once quickly when the power button is pressed on the remote or the TV, the 2200uf 10v filter capacitor on the SMPS has failed. This capacitor is located in the upper right side of the power supply close to the cable that connects the main board. Visual inspection will normally show that it has a swollen top. Replace capacitor and inspect the others in the filter stage to restore operation.
Samsung
LNS4051DX/XAA LCD TV
Symptom: Dead backlight flashes on then off.
> Unit would flash on then off and audio would work. You could saw video with a flashlight. Sometimes unit would stay on and run if you cycled on and off many times. Found bad solder connection on IP board TI801 on primary side.
Re-soldered and problem solved.
Samsung LNT4065FX/XAA, LNT4665FX/XAA,
LNT5265FX/XAA, LNT4061FX/XAA, LNT4661FX/XAA LCD TV
Symptom: Half screen is purple colour.
> Half screen is purple color. That’s mean LCD panel controller board is defective. Panel needs to be replaced.
Samsung LN32C350D1DXZA LCD TV
Symptom: Multiple Vertical lines.
> Try to call out the OSD Menu, the multiple vertical lines that do not go through the OSD menu. If the symptom does not affect the OSD menu (as shown above) or does not appear in the test picture, replace the main board only. Do not replace the LVDS or T-Con board or the LCD Panel.
Samsung LN-52A850 LCD TV
Symptom: The image breaks up or doubles images on the right side of the screen.
> Replace T-CON board and problem solved.
Symptom: Dead backlight flashes on then off.
> Unit would flash on then off and audio would work. You could saw video with a flashlight. Sometimes unit would stay on and run if you cycled on and off many times. Found bad solder connection on IP board TI801 on primary side.
Re-soldered and problem solved.
Samsung LNT4065FX/XAA, LNT4665FX/XAA,
LNT5265FX/XAA, LNT4061FX/XAA, LNT4661FX/XAA LCD TV
Symptom: Half screen is purple colour.
> Half screen is purple color. That’s mean LCD panel controller board is defective. Panel needs to be replaced.
Samsung LN32C350D1DXZA LCD TV
Symptom: Multiple Vertical lines.
> Try to call out the OSD Menu, the multiple vertical lines that do not go through the OSD menu. If the symptom does not affect the OSD menu (as shown above) or does not appear in the test picture, replace the main board only. Do not replace the LVDS or T-Con board or the LCD Panel.
Samsung LN-52A850 LCD TV
Symptom: The image breaks up or doubles images on the right side of the screen.
> Replace T-CON board and problem solved.
Samsung
LN46B530P7NXZA LCD TV
Symptom: There is color distortion on objects or people’s faces.
> The LVDS cable can cause this if it isn’t seated correctly. Check the position of the LVDS cable and the contacts. If it is seated correctly, replace the LVDS cable.
Samsung LNT4661FX/XAA LCD TV
Symptom: Half of the screen is black or purple on all inputs.
> When call out the OSD menu, the problem also affects the OSD menu, replace the LCD panel.
Samsung LNT5271FX LCD TV
Symptom: Left side of the screen is dark. The right side of the screen have horizontal lines with distorted video.
> The symptom also affects the OSD Menu, so replace the T-CON board then problem solved.
Symptom: There is color distortion on objects or people’s faces.
> The LVDS cable can cause this if it isn’t seated correctly. Check the position of the LVDS cable and the contacts. If it is seated correctly, replace the LVDS cable.
Samsung LNT4661FX/XAA LCD TV
Symptom: Half of the screen is black or purple on all inputs.
> When call out the OSD menu, the problem also affects the OSD menu, replace the LCD panel.
Samsung LNT5271FX LCD TV
Symptom: Left side of the screen is dark. The right side of the screen have horizontal lines with distorted video.
> The symptom also affects the OSD Menu, so replace the T-CON board then problem solved.
Samsung LNS4051DX/XAA LCD TV
Symptom: Clicking repeatedly TV will not turn on
> Found 2 electrolytic 100uf at 16v capacitors on the 5v line C115 and C123 bad.
Or replace the power supply.
Samsung LNS4051DX/XAA LCD TV
Symptom: Dead Backlight Flashes On then Off.
UNIT WOULD FLASH ON THEN OFF AND AUDIO WOULD WORK. YOU COULD SEE VIDEO WITH A FLASHLIGHT. SOMETIMES UNIT WOULD STAY ON AND RUN IF YOU CYCLED ON AND OFF MANY TIMES. FOUND BAD SOLDER CONNECTION ON IP BOARD TI801 ON PRIMARY SIDE. RESOLDERED AND CORRECTED PROBLEM.
Samsung LNS4692DX/XAA LCD TV
Symptom: No video TV but has backlight and audio. TV will not come on.
> Found pico fuse open at cp1 on the T-CON PCB. If shorted CP1 with a wire jumper, TV comes on and runs fine. Replace the Pico fuse or T-CON PCB.
Samsung LNT3242HX/XAA, LNT3232HX/XAA LCD TV
Symptom: Can’t power on.
> TV would not come on. Removed the back and as soon as we did the set came on. Found glue was around cables on the SMPS. Cleaned glue off and cleaned the terminals. Set operates normally.
Samsung LNT3253HX/XAA LCD TV
Symptom: After a few minutes when TV warms-up picture becomes distorted
> 10-15 minutes after you turned on the unit panel warms-up and picture becomes distorted. If you just push the TV's frame picture becomes even more distorted. On the back of the panel the CONTROL ASIC area is very hot. Replace the panel to fix the problem.
Samsung LNT4065FX/XAA, LNT4665FX/XAA,
LNT5265FX/XAA, LNT4061FX/XAA, LNT4661FX/XAA LCD TV
Symptom: Blue screen without signal. If provide with signal the blue screen
will flash white short horizontal lines.
> Refit or replace LVDS cable, check if the cable not strangled by the metal cover and loosen up the screws of the cover.
Samsung
LNT4665FX/XAA LCD TV
Symptom: Brightness lost after replaced MAIN PCB.
> Because MAIN PCB BN94-01199E is designed to work with both models LNT4665FX/XAA and LNT4661FX/XAA when you replaced the board is possible to lost the brightness. Go in SERVICE MODE and turn value LVDS BYTE from 8 to 10.
Samsung LNT5271FX/XAA, LNT4671FX/XAA LCD TV
Symptom: TV is cycling, the red LED light blinking and the relay is cycling sometime TV will come on.
> TV is cycling, the red LED light blinking and the relay is cycling sometime TV will come on. Even the Main board replaced, did not fix. This was a used unit, found cable from the main board to the side AV jack was reversed, is not labeled as to direction of use. This cable if reversed will be hot to the touch.
Found by removing and re-plugging and changing direction of cable TV worked.
This was tried on both model numbers with the same result.
Symptom: Brightness lost after replaced MAIN PCB.
> Because MAIN PCB BN94-01199E is designed to work with both models LNT4665FX/XAA and LNT4661FX/XAA when you replaced the board is possible to lost the brightness. Go in SERVICE MODE and turn value LVDS BYTE from 8 to 10.
Samsung LNT5271FX/XAA, LNT4671FX/XAA LCD TV
Symptom: TV is cycling, the red LED light blinking and the relay is cycling sometime TV will come on.
> TV is cycling, the red LED light blinking and the relay is cycling sometime TV will come on. Even the Main board replaced, did not fix. This was a used unit, found cable from the main board to the side AV jack was reversed, is not labeled as to direction of use. This cable if reversed will be hot to the touch.
Found by removing and re-plugging and changing direction of cable TV worked.
This was tried on both model numbers with the same result.
Samsung LN32B360C5DXZA,LN32B530P7FXZA,LN32B650T1FXZA,LN32B460B2DXZA,LN32B540P8DXZA,LN32B550K1FXZA,LN32B640R3FXZA,LN32B457C6HXZA,LN32B450C4HXZA,LN37B457C6HXZA,LN37B530P7FXZA,LN37B650T1FXZA,LN37B550K1FXZA,LN40B457C6HXZA,LN40B550K1HXZA,LN40B 500P3FXZA,LN40B550K1FXZA,LN40B650T1FXZA,LN40B530P7FXZA,LN40B530P7NXZA,LN40B750U1FXZA,LN40B 540P8FXZA,LN40B610A5FXZA,LN40B630N1FXZA,
LN40B640R3FXZA,LN46B650T1FXZA,LN46B530P7NXZA,LN46B530P7FXZA,LN46B550K1FXZA,LN46B610A5FXZA,LN46B540P8FXZA,LN46B630N1FXZA,LN46B640R3FXZA,LN46B 750U1FXZA,LN52B550K1HXZA,LN52B610A5FXZA,LN52B550K1FXZA,LN52B540P8FXZA,LN52B530P7FXZA,LN52B630N1FXZA,LN52B750U1FXZA,LN55B640R3FXZA,LN55B650T1FXZA LCD TV
Symptom: Firmware blinking in Red at the top of the screen
Problem - After changing the main board, I'm now stuck with the firmware blinking in RED print at the top of the screen.
> The unit is stuck in aging mode. To exit, simply hit the menu button on the TV itself.
Samsung LN32B360C5DXZA,LN32B530P7FXZA,LN32B460B2DXZA,LN32B540P8DXZA,LN32B550K1FXZA,LN37B530P7FXZA,LN37B550K1FXZA,LN40B550K1FXZA,LN40B530P7FXZA,LN40B 530P7NXZA,LN40B530P7FXZC,LN40B540P8FXZA,LN46B530P7NXZA,LN46B530P7FXZA,LN46B550K1FXZA,LN46B 540P8FXZA
Symptom:
Flickering on the screen intermittently
When the unit is connected via HDMI to a Scientific Atlanta cable set top box set in by pass mode for resolutions 480p and 720p a flickering will occur.
> Change the cable box to a fixed resolution. OR have the customer install the latest TV firmware which can be located on samsung.com.
Samsung
LN46A550P3FXZA,LN46A650A1FXZA,LN46A530P1FXZA,LN46A750R1FXZA,LN46A860S2FXZA,LN46A950D1FXZA,LN46A540P2FXZA,LN46A850S1FXZA,LN46A630M1FXZA,LN46A 580P6FXZA,LN52A530P1FXZA,LN52A750R1FXZA,LN52A650A1FXZA,LN52A550P3FXZA,LN52A630M1FXZA,LN52A 860S2FXZA,LN52A850S1FXZA,LN52A540P2FXZA,
LN40A530P1FXZA,LN40A450C1DXZA,LN40A330J1DXZA,LN40A 550P3FXZA,LN40A650A1FXZA,LN40A630M1FXZA,LN40A540P2FXZA LCD TV
Symptom: Unit cycles on/off during start-up.
> If the unit tries to turn on but begins to cycle on and off before any video is displayed and all of the SMPS voltages are good, disconnect the LVDS cable at the T-Con board. If the set starts and the backlights come on, replace the T-Con board. If the set does not start, disconnect the LVDS cable at the main board. If the set starts, replace the LVDS cable. If the set still does not start-up, replace the main board.
Samsung
LN32A330J1DXZA,LN32A450C1DXZA,LN32A650A1FXZA,LN32A 550P3FXZA,LN32A540P2DXZA,LN32A330J1NXZA,LN32A300J1DXZA,LN40A530P1FXZA,LN40A450C1DXZA,LN40A750R1FXZA,LN40A 330J1D
XZA,LN40A550P3FXZA,LN40A540P2FXZA,LN40A500T1FXZA,LN46A530P1FXZA,LN46A860S2FXZA,LN46A750R1FXZA,LN46A 550P3F
XZA,LN46A650A1FXZA,LN46A950D1FXZA,LN46A540P2FXZA,LN46A500T1FXZA,LN46A850S1FXZA,LN46A630M1FXZA,LN46A 850S1F
XZX,LN46A580P6FXZA,LN52A530P1FXZA,LN52A750R1FXZA,LN52A650A1FXZA,LN52A550P3FXZA,LN52A630M1FXZA,LN52A 860S2F
XZA,LN52A850S1FXZA,LN52A540P2FXZA,LN52A580P6FXZA
Symptom: Auto-shutdown on 2008 LCD TV’s.
> Upon inspections of 2008 LCD TV's we have found that the LVDS (ribbon cable) can cause an auto shut down. Even if the LVDS cable doesn’t look defective try changing it anyway and retest the TV. It is a good practice to carry a few extra LVDS cables for such testing circumstances.
Samsung
LN32B360C5DXZA,LN32B530P7FXZA,LN32B650T1FXZA,LN32B 460B2DXZA,LN32B540P8DXZA,LN32B550K1FXZA,LN32B640R3FXZA,
LN32B457C6HXZA,LN32B450C4HXZA,LN32B540P8DUZA,LN32B 450C3HXZA,LN32B460B2DUZA,LN32B360C5DUZA,LN32B550K1FUZA,
LN32B530P7FUZA,LN32B450C3HUZA,LN40B530P7FUZA,LN40B 550K1FUZA,LN40B457C6HXZA,LN40B550K1HXZA,LN40B610A5FUZA,
LN40B640R3FUZA,LN40B650T1FUZA,LN40B630N1FUZA,LN40B 540P8FUZA,LN40B500P3FXZA,LN40B550K1FXZA,LN40B650T1FXZA,
LN40B530P7FXZA,LN40B530P7NXZA,LN40B750U1FXZA,LN40B 540P8FXZA,LN40B630N1FXZA,LN40B640R3FXZA,LN52B550K1HXZA,
LN52B610A5FXZA,LN52B550K1FXZA,LN52B540P8FXZA,LN52B 530P7FXZA,LN52B630N1FXZA, LN52B750U1FXZA LCD TV
Symptom: Backlight Failure Testing.
> Backlight failures can be partial or full failure check the backlight supply voltage (refer to service manual). If supply voltage is present, use a flashlight behind the television and shine a light through the panel. If the video is working you will see it.
When the unit is connected via HDMI to a Scientific Atlanta cable set top box set in by pass mode for resolutions 480p and 720p a flickering will occur.
> Change the cable box to a fixed resolution. OR have the customer install the latest TV firmware which can be located on samsung.com.
Samsung
LN46A550P3FXZA,LN46A650A1FXZA,LN46A530P1FXZA,LN46A750R1FXZA,LN46A860S2FXZA,LN46A950D1FXZA,LN46A540P2FXZA,LN46A850S1FXZA,LN46A630M1FXZA,LN46A 580P6FXZA,LN52A530P1FXZA,LN52A750R1FXZA,LN52A650A1FXZA,LN52A550P3FXZA,LN52A630M1FXZA,LN52A 860S2FXZA,LN52A850S1FXZA,LN52A540P2FXZA,
LN40A530P1FXZA,LN40A450C1DXZA,LN40A330J1DXZA,LN40A 550P3FXZA,LN40A650A1FXZA,LN40A630M1FXZA,LN40A540P2FXZA LCD TV
Symptom: Unit cycles on/off during start-up.
> If the unit tries to turn on but begins to cycle on and off before any video is displayed and all of the SMPS voltages are good, disconnect the LVDS cable at the T-Con board. If the set starts and the backlights come on, replace the T-Con board. If the set does not start, disconnect the LVDS cable at the main board. If the set starts, replace the LVDS cable. If the set still does not start-up, replace the main board.
Samsung
LN32A330J1DXZA,LN32A450C1DXZA,LN32A650A1FXZA,LN32A 550P3FXZA,LN32A540P2DXZA,LN32A330J1NXZA,LN32A300J1DXZA,LN40A530P1FXZA,LN40A450C1DXZA,LN40A750R1FXZA,LN40A 330J1D
XZA,LN40A550P3FXZA,LN40A540P2FXZA,LN40A500T1FXZA,LN46A530P1FXZA,LN46A860S2FXZA,LN46A750R1FXZA,LN46A 550P3F
XZA,LN46A650A1FXZA,LN46A950D1FXZA,LN46A540P2FXZA,LN46A500T1FXZA,LN46A850S1FXZA,LN46A630M1FXZA,LN46A 850S1F
XZX,LN46A580P6FXZA,LN52A530P1FXZA,LN52A750R1FXZA,LN52A650A1FXZA,LN52A550P3FXZA,LN52A630M1FXZA,LN52A 860S2F
XZA,LN52A850S1FXZA,LN52A540P2FXZA,LN52A580P6FXZA
Symptom: Auto-shutdown on 2008 LCD TV’s.
> Upon inspections of 2008 LCD TV's we have found that the LVDS (ribbon cable) can cause an auto shut down. Even if the LVDS cable doesn’t look defective try changing it anyway and retest the TV. It is a good practice to carry a few extra LVDS cables for such testing circumstances.
Samsung
LN32B360C5DXZA,LN32B530P7FXZA,LN32B650T1FXZA,LN32B 460B2DXZA,LN32B540P8DXZA,LN32B550K1FXZA,LN32B640R3FXZA,
LN32B457C6HXZA,LN32B450C4HXZA,LN32B540P8DUZA,LN32B 450C3HXZA,LN32B460B2DUZA,LN32B360C5DUZA,LN32B550K1FUZA,
LN32B530P7FUZA,LN32B450C3HUZA,LN40B530P7FUZA,LN40B 550K1FUZA,LN40B457C6HXZA,LN40B550K1HXZA,LN40B610A5FUZA,
LN40B640R3FUZA,LN40B650T1FUZA,LN40B630N1FUZA,LN40B 540P8FUZA,LN40B500P3FXZA,LN40B550K1FXZA,LN40B650T1FXZA,
LN40B530P7FXZA,LN40B530P7NXZA,LN40B750U1FXZA,LN40B 540P8FXZA,LN40B630N1FXZA,LN40B640R3FXZA,LN52B550K1HXZA,
LN52B610A5FXZA,LN52B550K1FXZA,LN52B540P8FXZA,LN52B 530P7FXZA,LN52B630N1FXZA, LN52B750U1FXZA LCD TV
Symptom: Backlight Failure Testing.
> Backlight failures can be partial or full failure check the backlight supply voltage (refer to service manual). If supply voltage is present, use a flashlight behind the television and shine a light through the panel. If the video is working you will see it.
Samsung
LNT4069FX/XAA,LNT4066FX/XAA,LNT4669FX/XAA,LNT3255HTX/XAA,LNT375HAX/XAA,LNT4042HX/XAA,LNT325HAX/XAA,LNT405HAX/X
AA,LNT2353HTX/XAA,LNT3753HX/XAA,LNT2653HTX/XAA,LNT3242HTX/XAA,LNT3253HTX/XAA,LNT4042HTX/XAA,LNT4053HTX/XAA,LNT
4071FX/XAA,LNT4671FX/XAA,LNT5271FX/XAA,LNT4642HX/XAA,LNT466FX/XAA,LNT4065FX/XAA,LNT4665FX/XAA,LNT5265FX/XAA,LNT26
32HX/XAA,LNT2642HX/XAA,LNT2653HX/XAA,LNT3232HX/XAA,LNT3242HX/XAA,LNT3253HX/XAA,LNT3732HX/XAA,LNT4032HX/XAA,LNT
4053HX/XAA,LNT4061FX/XAA,LNT4661FX/XAA LCD TV
Symptom: Intermittent LCD Video Troubleshooting.
> Troubleshooting intermittent video problems can be time consuming, but these tips may help narrow down the cause of an intermittent video problem. The very first thing to do is to make sure the customer does not have OSD. They can verify this by just pressing Menu or Volume on their TV remote control. If they do have OSD, then the problem is most likely in the source and not the TV.
The next step when encountering an intermittent video problem is to find out if the backlights are on when the set looses video. You can probably obtain this information from the customer before you schedule the call. Ask if they noticed if the screen is completely black or if it is lit up slightly when the video goes out. They may be able to notice it better if they stand at an angle to the TV and turn it on or off and see if there is any change in brightness. If the backlights are out, you need to know if the set ever has video when they
turn it on, or does it go out after they have had the set on for a period of time. If the set occasionally will not have backlights when it is first turned on, suspect the panel or power supply/IP board. If the set has video for a while and then looses the backlights, suspect a power supply/IP board or main board. Typically the panel will cause a no backlight at turn on, while the power supply and Main Board will cause the backlights to go out after a period of time. If the set has backlights when first turned on and the lights change their brightness in several steps before quickly going out, suspect the IP board. If the backlights are on when the set loses video after it has been on for a while, most likely the LVDS cable is defective. If the set has backlights but no video when it is first turned on, the T/Con or Main Board would probably be at fault. Always check the simple things first, like a LVDS cable that is not plugged in properly or a power connector to the panel being loose. There are exceptions to every rule, but this generally should help with narrowing down no video in LCD sets.
Samsung LN32A450C1DXZA, LN32A450C1HXZA,LN32A450C3HXZA, LN32A330J1DXZA, LN32A330J1NXZA LCD TV
Symptom: Video will intermittently turn mostly white.
White screen with a faint image of OSD and video is in the background. Video will intermittently turn mostly white with the OSD barely visible in the background. Even a black image or when the panel should not be showing any video, it is white. Found that one of the sub-boards inside the panel, the boards that the ribbon cable from the T-Con connect to, are not seated properly and the larger SMD capacitors on the board are intermittently making contact with the metal frame of the set, effectively creating a short to ground.
This is one of the panels that are mounted upside down, so the stand mounts just below and behind the panel frame. Any slight pressure from the stand can cause the frame to make contact. In many cases, the TV can be slightly flexed to make this issue occur.
Here, just beside a T-Con ribbon cable, you can see that the sub-board is not seated properly, and is in fact bowing towards the outer frame.
Samsung LNT4061FX/XAA, LN32A450C1DXZC,
LN32A550P3FXZC, LN32A550P3FXZX, LN32A450C1DXZX,LN32A650A1FXZA, LN32A450C1XZD, LN32A450C1DXZA,
LN32A540P2DXZA, LN32A450C1XZP, LN32A550P3RXZD,LN40A530P1FXZA, LN40A530P1FXZX, LN40A450C1HXZX,
LN40A450C1DXZA, LN40A750R1FXZA, LN40A450C1DXZX,LN40A530P1FXZC, LN40A550P3FXZC, LN40A650A1FXZC,
LN40A550P3FXZX, LN40A750R1FXZC, LN40A330J1DXZX,LN40A650A1FXZX, LN40A450C1XZD, LN40A450C1DXZC,
LN40A330J1DXZA, LN40A550P3FXZA, LN40A650A1FXZA,LN40A750R1FXZX, LN40A550P3RXZD, LN40A330J1XZD,
LN40A630M1FXZA, LN40A540P2FXZA, LN40A650A2RXZD,LN40A630M1FXZC, LN40A630M1FXZX, LN40A610A3RXZD,
LN40A500T1FXZA, LN40A330J1XZP, LN40A450C1XZP,LN40A650A1RXZP, LN40A610A1RXZD, LN40A650A1FXZD LCD TV
Symptom: Troubleshooting Inverter PCB boards
> The inverter PCB is the power supply for the Cold Cathode Fluorescent tubes. The inverter acts exactly like the ballast used in a standard fluorescent light fixture. In the case of an LCD TV, 24 volts from the power supply is applied to a switch mode power supply (SMPS). The SMPS outputs ~1000 Volts to energize the bulbs then the voltage drops to ~ 500 volts for run operation. The SMPS switching frequency is around 90 KHz.
The first step for verifying inverter board operation is to confirm the 24 volt supply is present. An oscilloscope can also be used to verify the SMPS circuit is oscillating. Simply holding the oscilloscope probe in the area of the switching transformer will show screen activity if the switching action is taking place. Measuring the SMPS output with standard equipment is not recommended as this is high voltage and at a high frequency.
LNT4069FX/XAA,LNT4066FX/XAA,LNT4669FX/XAA,LNT3255HTX/XAA,LNT375HAX/XAA,LNT4042HX/XAA,LNT325HAX/XAA,LNT405HAX/X
AA,LNT2353HTX/XAA,LNT3753HX/XAA,LNT2653HTX/XAA,LNT3242HTX/XAA,LNT3253HTX/XAA,LNT4042HTX/XAA,LNT4053HTX/XAA,LNT
4071FX/XAA,LNT4671FX/XAA,LNT5271FX/XAA,LNT4642HX/XAA,LNT466FX/XAA,LNT4065FX/XAA,LNT4665FX/XAA,LNT5265FX/XAA,LNT26
32HX/XAA,LNT2642HX/XAA,LNT2653HX/XAA,LNT3232HX/XAA,LNT3242HX/XAA,LNT3253HX/XAA,LNT3732HX/XAA,LNT4032HX/XAA,LNT
4053HX/XAA,LNT4061FX/XAA,LNT4661FX/XAA LCD TV
Symptom: Intermittent LCD Video Troubleshooting.
> Troubleshooting intermittent video problems can be time consuming, but these tips may help narrow down the cause of an intermittent video problem. The very first thing to do is to make sure the customer does not have OSD. They can verify this by just pressing Menu or Volume on their TV remote control. If they do have OSD, then the problem is most likely in the source and not the TV.
The next step when encountering an intermittent video problem is to find out if the backlights are on when the set looses video. You can probably obtain this information from the customer before you schedule the call. Ask if they noticed if the screen is completely black or if it is lit up slightly when the video goes out. They may be able to notice it better if they stand at an angle to the TV and turn it on or off and see if there is any change in brightness. If the backlights are out, you need to know if the set ever has video when they
turn it on, or does it go out after they have had the set on for a period of time. If the set occasionally will not have backlights when it is first turned on, suspect the panel or power supply/IP board. If the set has video for a while and then looses the backlights, suspect a power supply/IP board or main board. Typically the panel will cause a no backlight at turn on, while the power supply and Main Board will cause the backlights to go out after a period of time. If the set has backlights when first turned on and the lights change their brightness in several steps before quickly going out, suspect the IP board. If the backlights are on when the set loses video after it has been on for a while, most likely the LVDS cable is defective. If the set has backlights but no video when it is first turned on, the T/Con or Main Board would probably be at fault. Always check the simple things first, like a LVDS cable that is not plugged in properly or a power connector to the panel being loose. There are exceptions to every rule, but this generally should help with narrowing down no video in LCD sets.
Samsung LN32A450C1DXZA, LN32A450C1HXZA,LN32A450C3HXZA, LN32A330J1DXZA, LN32A330J1NXZA LCD TV
Symptom: Video will intermittently turn mostly white.
White screen with a faint image of OSD and video is in the background. Video will intermittently turn mostly white with the OSD barely visible in the background. Even a black image or when the panel should not be showing any video, it is white. Found that one of the sub-boards inside the panel, the boards that the ribbon cable from the T-Con connect to, are not seated properly and the larger SMD capacitors on the board are intermittently making contact with the metal frame of the set, effectively creating a short to ground.
This is one of the panels that are mounted upside down, so the stand mounts just below and behind the panel frame. Any slight pressure from the stand can cause the frame to make contact. In many cases, the TV can be slightly flexed to make this issue occur.
Here, just beside a T-Con ribbon cable, you can see that the sub-board is not seated properly, and is in fact bowing towards the outer frame.
Samsung LNT4061FX/XAA, LN32A450C1DXZC,
LN32A550P3FXZC, LN32A550P3FXZX, LN32A450C1DXZX,LN32A650A1FXZA, LN32A450C1XZD, LN32A450C1DXZA,
LN32A540P2DXZA, LN32A450C1XZP, LN32A550P3RXZD,LN40A530P1FXZA, LN40A530P1FXZX, LN40A450C1HXZX,
LN40A450C1DXZA, LN40A750R1FXZA, LN40A450C1DXZX,LN40A530P1FXZC, LN40A550P3FXZC, LN40A650A1FXZC,
LN40A550P3FXZX, LN40A750R1FXZC, LN40A330J1DXZX,LN40A650A1FXZX, LN40A450C1XZD, LN40A450C1DXZC,
LN40A330J1DXZA, LN40A550P3FXZA, LN40A650A1FXZA,LN40A750R1FXZX, LN40A550P3RXZD, LN40A330J1XZD,
LN40A630M1FXZA, LN40A540P2FXZA, LN40A650A2RXZD,LN40A630M1FXZC, LN40A630M1FXZX, LN40A610A3RXZD,
LN40A500T1FXZA, LN40A330J1XZP, LN40A450C1XZP,LN40A650A1RXZP, LN40A610A1RXZD, LN40A650A1FXZD LCD TV
Symptom: Troubleshooting Inverter PCB boards
> The inverter PCB is the power supply for the Cold Cathode Fluorescent tubes. The inverter acts exactly like the ballast used in a standard fluorescent light fixture. In the case of an LCD TV, 24 volts from the power supply is applied to a switch mode power supply (SMPS). The SMPS outputs ~1000 Volts to energize the bulbs then the voltage drops to ~ 500 volts for run operation. The SMPS switching frequency is around 90 KHz.
The first step for verifying inverter board operation is to confirm the 24 volt supply is present. An oscilloscope can also be used to verify the SMPS circuit is oscillating. Simply holding the oscilloscope probe in the area of the switching transformer will show screen activity if the switching action is taking place. Measuring the SMPS output with standard equipment is not recommended as this is high voltage and at a high frequency.
Samsung
LN40A650A1FXZA, LN46A650A1FXZA,LN40A750R1FXZC, LN46A750R1FXZA, LN40A750R1FXZA
LCD TV
Symptom: Unit tries to start with melody but cycles off and back on.
> If the unit tries to turn on and makes the start-up melody but then immediately shuts off and starts again, unplug the LVDS cable and apply power again. If the set stays on, replace the T-Con board.
Symptom: Unit tries to start with melody but cycles off and back on.
> If the unit tries to turn on and makes the start-up melody but then immediately shuts off and starts again, unplug the LVDS cable and apply power again. If the set stays on, replace the T-Con board.
Model/s:
Samsung LNT4071FX/XAA, LNT4671FX/XAA,LNT5271FX/XAA LCD TV
Symptom: Video Stuttering or Hesitation
> The customer may complain that the video has a stutter or hesitation when viewing regular program, either standard definition or high definition.
To fix, go into the customer menu, select Picture, then scroll to Auto Motion Plus 120Hz and select Off. This enhancement circuit works for some movies, but can introduce severe hesitations and ghosting on regular programming. The customer should also be informed that this does not affect the 120Hz operation of the panel. The panel operates at 120Hz regardless of this setting.
Samsung LN52A650A1FXZA, LN40A650A1FXZA,LN46A650A1FXZA, LN52A650A1FXZC, LN46A650A1FXZC LCD TV
Symptom: Will not turn on, cycles on and off with start-up melody, no backlights
> If the set will try to turn on and the start-up melody sounds but no backlight appears and the set cycles off and on every 5 to 10 seconds, unplug the LVDS cable from the T-Con/FRC board. If the set then runs and the backlights come on and stay on, replace the defective T-Con/FRC board.
Samsung LNT4069FX/XAA,LNT4066FX/XAA,LNT4669FX/XAA,LNT4071FX/XAA,LNT4671FX/XAA,LNT5271FX/XAA,LNT4065FX/XAA,LNT4665FX/XAA,LNT5265FX/XAA,LNT4061FX/XAA,LNT4661FX/XAA
Symptom: Unit cycles on and off several times before starting.
> If the unit will cycle on and off several times before turning on and then playing fine, check the power supply carefully for filter capacitors with bulged tops. Replace the capacitors or power supply to correct the issue.
Symptom: Video Stuttering or Hesitation
> The customer may complain that the video has a stutter or hesitation when viewing regular program, either standard definition or high definition.
To fix, go into the customer menu, select Picture, then scroll to Auto Motion Plus 120Hz and select Off. This enhancement circuit works for some movies, but can introduce severe hesitations and ghosting on regular programming. The customer should also be informed that this does not affect the 120Hz operation of the panel. The panel operates at 120Hz regardless of this setting.
Samsung LN52A650A1FXZA, LN40A650A1FXZA,LN46A650A1FXZA, LN52A650A1FXZC, LN46A650A1FXZC LCD TV
Symptom: Will not turn on, cycles on and off with start-up melody, no backlights
> If the set will try to turn on and the start-up melody sounds but no backlight appears and the set cycles off and on every 5 to 10 seconds, unplug the LVDS cable from the T-Con/FRC board. If the set then runs and the backlights come on and stay on, replace the defective T-Con/FRC board.
Samsung LNT4069FX/XAA,LNT4066FX/XAA,LNT4669FX/XAA,LNT4071FX/XAA,LNT4671FX/XAA,LNT5271FX/XAA,LNT4065FX/XAA,LNT4665FX/XAA,LNT5265FX/XAA,LNT4061FX/XAA,LNT4661FX/XAA
Symptom: Unit cycles on and off several times before starting.
> If the unit will cycle on and off several times before turning on and then playing fine, check the power supply carefully for filter capacitors with bulged tops. Replace the capacitors or power supply to correct the issue.
Samsung LN26B460B2DXZA; LN26B360C5DXZA; LN26B457C6HXZA; LN32B460B2DXZA; LN32B360C5DXZA; LN32B540P8DXZA; LN32B457C6HXZA;LN32B530P7FXZA;LN32B550K1FXZA; LN37B530P7FXZA; LN37B550K1FXZA;LN37B650T1FXZA
Symptom: No Backlight but sound ok.
TV will power up but have no backlight operation (No display). Sound is OK.
Procedure:
1. Verify that the TV is within the serial number range by checking the ninth digit in the serial number (i.e. AZ4D3CTS5 Ninth digit is a 5).
2. If the digit is 4 or 5, check the number on the diode itself to verify whether it has already been replaced.
3. If the diode has “0907”, “0908” or “0909” on its case (refer to photos 1 & 2), replace with new (Part number 0402-001415).
Verify the cause of the symptom by measuring (in circuit) across the diode (location DP805) (see photos 3 through 6). If the resistance measures between 500 and 600 ohms, the diode is good and therefore the symptom is being caused by a different reason. If the resistance measurement approaches zero ohms (shorted) the diode is defective and needs to be replaced using part number 0402-001415.
> There are two versions of the IP board with different physical layouts using the same diode type. Replace the diode using standard soldering methods for a lead-free application. If the diode is not available, order the IP Board