REPAIRING AND NOT THROWING AWAY

Richtige Fernseher haben Röhren!

Richtige Fernseher haben Röhren!

In Brief: On this site you will find pictures and technical information about Service Modes, Circuit Diagrams, Firmware Update procedure, Disassemble procedure, Universal remote control set-up codes, Troubleshooting and more....

If you go into the profession, you will obtain or have access to a variety of tech tips databases HERE IT IS Master Electronics Repair !.

These are an excellent investment where the saying: 'time-is-money' rules. However, to learn, you need to develop a general troubleshooting approach - a logical, methodical, method of narrowing down the problem. A tech tip database might suggest: 'Replace C536' for a particular symptom. This is good advice for a specific problem on one model. However, what you really want to understand is why C536 was the cause and how to pinpoint the culprit in general even if you don't have a service manual or schematic and your tech tip database doesn't have an entry for your sick TV or VCR.

While schematics are nice, you won't always have them or be able to justify the purchase for a one-of repair. Therefore, in many cases, some reverse engineering will be necessary. The time will be well spent since even if you don't see another instance of the same model in your entire lifetime, you will have learned something in the process that can be applied to other equipment problems.
As always, when you get stuck, checking out a tech-tips database may quickly identify your problem and solution.In that case, you can greatly simplify your troubleshooting or at least confirm a diagnosis before ordering parts.

Happy repairing!
Today, the West is headed for the abyss. For the ultimate fate of our disposable society is for that society itself to be disposed of. And this will happen sooner, rather than later.

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Showing posts with label TCL. Show all posts
Showing posts with label TCL. Show all posts

Monday, 22 February 2021

REPAIRING / SERVICING TV TCL L32S6300

Technical description and composition of the TCL L32S6300 TV, panel type and modules used. The composition of the modules.

TCL LED
Model: L32S6300

Chassis / Version: TPD.NT72563.PB771

Panel: LVW320ND1L

LED driver (backlight): integrated into MainBoard

PWM LED driver: GB98TERN

MOSFET LED driver: TO-252

Power Supply (PSU): integrated into MainBoard

PWM Power: PWM SOT23-6

MOSFET Power: TO-220

MainBoard: TPD.NT72563.PB771

IC MainBoard: EMMC THGBMDG5D1LBAIL

Tuner: NoName

L32S6300 Specifications
TCL L32S6300
General recommendations for TV LCD LED repair
Possible malfunctions

- TCL L32S6300 TV does not turn on. There are no signs of operability. The indicators on the front panel do not light or blink, the TV does not respond to control buttons.

In such cases, the AC / DC converter of the mains voltage, which is combined with the main board TPD.NT72563.PB771, is often faulty. It is then necessary to measure its output voltages and, if they are absent, the power switches (TO-220) and rectifier diodes of the converters should be checked for the probability of a short circuit.
In case of breakdowns in the secondary circuits, the converter, as a rule, can operate in an emergency mode in a short-circuit mode, and in case of a short circuit in the power elements of the primary circuit, the mains fuse is usually cut off.
Breakdown of power switches (MosFet) in switching sources is sometimes caused by malfunctions of other circuit elements, for example, in the circuits supplying the PWM controller, frequency setting or damper, as well as in the circuits of Negative Feedback (OOS) stabilization. PWM controllers (PWM), if they do not have visible damage to the case and an outright short circuit between the terminals, are usually checked by replacing.

- There is no picture, but there is sound and reaction to the remote control. Or, for a second, the image may appear immediately after switching on.

The backlight of the matrix (LED panel) is usually faulty in these cases. Most often the reason for this is a break in the LEDs, or poor contact in the connectors of the brackets, less often the LED driver may be faulty.
To test the LED strips, in order to open all the transitions of the LEDs, several tens of volts or more are needed; it is best to use a current source for such purposes. The breakage of several PN junctions connected in series cannot be detected with a multimeter or tester. In such cases, it is necessary to open the panel and check each LED. If your multimeter cannot open the LED junctions in forward bias, you can sometimes detect the presence of a protective zener diode PN junction by connecting the probes in the opposite direction. If the zener diode is cut off or broken in K / Z, then the LED is faulty and needs to be replaced.

If TCL L32S6300 has no image, but there is sound, often the LVW320ND1L display backlight simply does not work. Moreover, in LED TVs, the LEDs inside the panel usually fail, less often the LED driver.
In such cases, you can see a barely noticeable image with a successful hit of external light on the screen.

Replacing the LEDs requires disassembling the LVW320ND1L LCD panel - a process that requires experience and qualifications from the master. We do not recommend doing such work on your own to owners of TVs and craftsmen who do not have experience in repairing LCD panels

If there is no image, and the backlight is on, the screen becomes slightly lighter when turned on, and in an open TV, light is visible through the holes in the panel case.
In this case, the panel may also be faulty - damage to strips, loops, for example, as a result of moisture ingress after unsuccessful washing of the screen, the T-CON (Timing Controller) board may be faulty. But often the main board MainBoard TPD.NT72563.PB771 also turns out to be faulty, a software failure is also possible.
Then, first of all, you need to check the panel supply voltage, fuses on the T-CON board, as well as the supply and reference voltages of the column and line drivers - VGH, VGL, Vcom.
If these measurements are within the normal range, it is necessary to trace the passage of LVDS signals from MainBoard TPD.NT72563.PB771 with an oscilloscope, as well as synchronizing signals to loops with drivers.

Flooded or unsuccessfully washed screens of LED TVs can be restored, in about half of the cases, usually if significant damage has not formed in the loops and panel strips.

- The TV does not go into operation, does not respond to the remote control. The indicator on the front panel is on or blinking.

Repair or diagnostics of the TPD.NT72563.PB771 motherboard should begin with checking the stabilizers and power converters necessary to power the microcircuits and matrix. If necessary, you should update or replace the software (software). In cases of complex MB (SSB) repairs and with the necessary skills and equipment, it may sometimes be necessary to replace its EMMC THGBMDG5D1LBAIL chips and other possible faulty components. Malfunctions associated with the use of BGA soldering technologies are usually easily diagnosed by the warm-up method.

Attention to TV owners! Attempts to repair the TCL L32S6300 yourself are not recommended by the manufacturer and can lead to serious negative consequences!


 

READ HOW TO REPAIR THE TV LED BACKLIGHT --------------> HERE.

 
Revision after repair of the backlight. Information from the master.

Reduce the backlight current from 92 mA to 66 mA - replaced one of the resistors (16 kOhm by 22 kOhm) at pin 6 ISET of the GB98TERN chip on the TPD.NT72563.PB771 board.
Additional MainBoard Repair

The appearance of the MainBoard TPD.NT72563.PB771 is shown in the figure below:



TPD.NT72563.PB771

Key features of the TCL L32S6300 device:

Installed matrix (LED panel) LVW320ND1L.
To power the backlight LEDs, a converter combined with the main board TPD.NT72563.PB771 is used, controlled by the GB98TERN PWM controller. TO-252 switches are used as power elements of the LED driver.
The power module is combined with the MainBoard and is made according to the AC / DC flyback voltage converter using SOT23-6 PWM microcircuits and TO-220 power switches. 


PWM SMPS in SOT-23-6, SOT-26, TSOP-6 packages

In the circuitry of modern switching power supplies (SMPS), PWM controllers made in small-sized planar packages with six terminals have gained wide popularity. The enclosure type designation can be SOT-23-6, SOT-23-6L, SOT-26, TSOP-6, SSOT-6. The appearance and arrangement of the pins are shown in the figure below. In this case, the code marking LD7530A is shown on the left fragment of the picture.


 

 Pin assignment:
1 - GND. (Common wire).
2 - FB. (FeedBack - Feedback). Input for controlling the duration of pulses with a signal from the output voltage. Sometimes it can be labeled COMP (input comparator).
3 - RI / RT / CT / COMP / NC - Depending on the type of microcircuit, it can be used for a frequency-setting RC circuit (RI / RT / CT), or for organizing protection, as an input of a PWM trip comparator at a threshold value at its input, specified in the document. In some types of microcircuits, this input may not be used in any way (NC - No Connect).
4 - SENSE, otherwise CS (Current Sense) - Input from the current sensor at the source of the key.
5 - VCC - Input voltage supply and start of the microcircuit.
6 - OUT (GATE) - Output for controlling the gate (Gate) of the key.

Functionally, these regulators work on the principle of the previously popular xx384x PWM microcircuits, which have proven themselves well in terms of reliability and stability.

Some difficulties often arise when replacing or choosing an analog for such PWM regulators due to the use of code markings in the designation of the type of microcircuits. The situation is complicated by a large number of component manufacturers who do not always provide documentation to the mass access, just as not all manufacturers of finished devices supply repair service centers with diagrams, so repairmen often have to study real circuit solutions by installed components and wiring connections directly on the board.

In practice, PWM microcircuits and the marking code EAxxx and Eaxxx are often found. Official documentation for them was not found in the public domain, but discussions on the forums and pieces of pictures from PDF from System General, which publishes them as SG6848T and SG6848T2, have survived. The drawing is here placed left .


 

For the attention of the masters, here below are PDF datasheet tables compiled from information available on the Internet and PDF documents for the selection of analogues types when replacing the most common six-legged planar PWM with pinout pins: pin1 - GND, pin2 - FB (COMP), pin4 - Sense, pin5 - Vcc, pin6 - OUT ...
Their main difference is the application and purpose of pin 3. 

 

NamePart NumberFabricantMarking
SG6849SG684965TZFairchild / ON SemiBBxx
SG6849SG6849-65T, SG6849-65TZSystem GeneralMBxx EBxx
SGP400SGP400TZ System General AAKxx

 

 PWM controllers (PWM) with a 95-100 kOhm resistor on pin 3.

When applying the PWM listed below, the frequency should be set with the RT (RI) resistor from pin 3 to ground. Usually its nominal value is chosen 95-100 kOhm for a frequency of 65-100 KHz. For more details, see the here below attached documentation. PDF files are packed in RAR.

 

NamePart NumberFabricantMarking
AP3103AAP3103AKTR-G1Diodes IncorporatedGHL
AP8263AP8263E6R, A8263E6VRAiT SemiconductorS1xx
AT3263AT3263S6ATC Technology3263
CR6848CR6848SChip-Rail848H16
CR6850CR6850SChip-Rail850xx
CR6851CR6851SChip-Rail851xx
FAN6602RFAN6602RM6XFairchild / ON SemiACCxx
FS6830FS6830FirstSemi
GR8830GR8830CGGrenergy30xx
GR8836GR8836C, GR8836CGGrenergy36xx
H6849H6849NFHI-SINCERITY
H6850H6850NFHI-SINCERITY
HT2263HT2263MPHOT-CHIP63xxx
KP201
Kiwi Instruments
LD5530LD5530GL LD5530RLeadtrandxxt30 xxt30R
LD7531LD7531GL, LD7531PLLeadtrendxxP31
LD7531ALD7531AGLLeadtrendxxP31A
LD7535/ALD7535BL, LD7535GL, LD7535ABL, LD7535AGLLeadtrendxxP35-xxx35A
LD7550LD7550BL, LD7550ILLeadtrendxxP50
LD7550BLD7550BBL, LD7550BILLeadtrend xxP50B
LD7551LD7551BL/ILLeadtrendxxP51
LD7551CLD7551CGLLeadtrendxxP51C
NX1049XN1049TPXian-Innuovo49xxx
OB2262OB2262MPOn-Bright-Electronics62xx
OB2263OB2263MPOn-Bright-Electronics63xx
PT4201PT4201E23FPowtech4201
R7731R7731GE/PERichtek0Q=
R7731AR7731AGERichtekIDP=xx
SD4870SD4870TRSilan Microelectronics4870
SF1530SF1530LGTSiFirst30xxx
SG5701SG5701TZSystem GeneralAAExx
SG6848SG6848T, SG6848T1, SG6848TZ1, SG6848T2Fairchild / ON SemiAAHxx EAxxx
SG6858SG6858TZFairchild / ON SemiAAIxx
SG6859ASG6859ATZ, SG6859ATYFairchild / ON SemiAAJFxx
SG6859SG6859TZFairchild / ON SemiAAJMxx
SG6860SG6860TYFairchildAAQxx
SP6850SP6850S26RGSporton Lab850xx
SP6853SP6853S26RGB, SP6853S26RGSporton Lab853xx
SW2263SW2263MPSamWin
UC3863/GUC3863G-AG6-RUnisonic Technologies CoU863 U863G
XN1049XN1049, XN1049TPInnuovo Microelectronics49 xxx

 

 PWM controllers that use pin 3 differently.

When using the following PWM (PWM controllers), you should pay attention to pin 3, which can be used to organize protection - thermal or from overvoltage of the input voltage.
The frequency can be fixed at 65kHz, or set by the value of the capacitor at pin 3.
When replacing any microcircuits with analogs, carefully study the documentation. PDF files are packed in a RAR archive.

 

NamePart NumberFabricantMarking
AP3105/V/L/RAP3105KTR-G1, AP3105VKTR-G1, AP3105LKTR-G1, AP3105RKTR-G1Diodes IncorporatedGHN GHO GHP GHQ
AP3105NA/NV/NL/NRAP3105NAKTR-G1, AP3105NVKTR-G1, AP3105NLKTR-G1, AP3105NRKTR-G1Diodes IncorporatedGKN GKO GKP GKQ
AP3125A/V/L/RAP3125AKTR-G1, AP3125VKTR-G1, AP3125LKTR-G1, AP3125RKTR-G1Diodes IncorporatedGLS GLU GNB GNC
AP3125BAP3125BKTR-G1Diodes IncorporatedGLV
AP3125HA/HBAP3125HAKTR-G1, AP3125HBKTR-G1Diodes IncorporatedGNP GNQ
AP31261AP31261KTR-G1Diodes IncorporatedGPE
AP3127/HAP3127KTR-G1, AP3127HKTR-G1Diodes IncorporatedGPH GSH
AP3301AP3301K6TR-G1Diodes IncorporatedGTC
FAN6862FAN6862TYFairchild / ON SemiABDxx
FAN6863FAN6863TY, FAN6863LTY, FAN6863RTYFairchild / ON SemiABRxx
HT2273HT2273TPHOT-CHIP73xxx
LD7510/JLD7510GL, LD7510JGLLeadtrendxxP10 xxP10J
LD7530/ALD7530PL, LD7530GL, LD7530APL, LD7530AGLLeadtrendxxP30 xxxP30A
LD7532LD7532GLLeadtrendxxP32
LD7532ALD7532AGLLeadtrendxxP32A
LD7532HLD7532HGLLeadtrendxxP32H
LD7533LD7533GLLeadtrendxxP33
LD7536LD7536GLLeadtrendxxP36
LD7536RLD7536RGLLeadtrendxxP36R
LD7537RLD7537RGLLeadtrendxxP37R
LD7539C GLLD7539C GLLeadtrendxxP39C
ME8204ME8204M6GMicrOneME8204xx
NCP1250NCP1250ASN65T1G, NCP1250BSN65T1G, NCP1250ASN100T1G, NCP1250BSN100T1GON Semiconductor25xxxx
NCP1251NCP1251ASN65T1G, NCP1251BSN65T1G, NCP1251ASN100T1G, NCP1251BSN100T1GON Semiconductor5xxxxx
OB2273OB2273MPOn-Bright-Electronics73xx
R7735R7735AGE, R7735HGE, R7735GGE, R7735RGE, R7735LGERichtek
UC3873/GUC3873-AG6-R, UC3873G-AG6-RUnisonic TechnologiesU873 U873G
 



TCL L32S6300 TV with LCD LVW320ND1L, diagonal size 32 "(81 cm) 16: 9 format. The brightness of the screen, declared by the manufacturer, 240 cd / m2 is realized by LED backlight. Contrast - the ratio of maximum brightness to minimum, is at least 3000 : 1. The technology of manufacturing the screen of this TV model is realized with LED backlighting.
LVW320ND1L sensor and MainBoard TPD.NT72563.PB771 software realize HD image quality at 1366x768 pixels in 720p (HD Ready).
The L32S6300 TV is equipped with SMART software, built-in applications and the ability to work on the Internet. Internet connection can be made via Wi-Fi wireless connection. Supported media file formats: MP3, MPEG4, MKV, JPEG.
The power of the acoustic system of sound is 10 W (2x5 W), provided by two speakers. Uses the NICAM stereo signal processing system and the Sound Surround function.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, component, HDMI x3, USB x2, Ethernet (RJ-45), Wi-Fi. A headphone output is provided. The digital tuner is capable of receiving television channels in the DVB-T, DVB-T2, DVB-C, DVB-S, DVB-S2 standards.

A power supply unit is used as part of the MainBoard.

Dimensions: with stand 734x476x184 mm, without stand 734x435x82 mm.

TV weight: with stand: 4.5 kg, without stand: 4.4 kg.

Attention! The LVW320ND1L panel of the TCL L32S6300 LED TV is an expensive and unreliable element.
Do not allow any impact on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it drips down the glass onto the cables to make the TV unrepairable. 

Wednesday, 10 February 2021

REPAIRING / SERVICING TV TCL L43S6400

 Technical description and composition of the TCL L43S6400 TV, panel type and modules used. The composition of the modules.

TCL LED
Model: L43S6400

Chassis / Version: TPD.RT2841.PB772

Panel: LVW430NDEL

LED driver (backlight): integrated into MainBoard

PWM LED driver: MP3398E

MOSFET LED driver: TO-252

Power Supply (PSU): integrated into MainBoard

PWM Power: PWM SOT23-6

MOSFET Power: N-FET TO-220F

MainBoard: TPD.RT2841.PB772

IC MainBoard: EMMC: H26M41204HPR (8Gb)

Tuner: DVBT / T2 & SAT

L43S6400 Specifications

 specifications! / Learn more ...
LCD TV LED Smart L43S6400 | Year of issue: 2019
Screen diagonal: 42.5 "(108 cm)
Screen format: 16: 9
Resolution: 1920x1080
Refresh rate: 60 Hz
LED backlight: yes, Direct LED
Smart: yes. Wi-Fi support - yes
Operating system: Android
HD support: 1080p Full HD, HDR
Brightness: 270 cd / m2
Contrast: 4000: 1
Viewing angle: 178 °
Pixel Response Time: 6.5ms
Progressive scan: yes
Digital tuner: DVB-T, DVB-T2, DVB-C, DVB-S, DVB-S2
Teletext: yes
Multimedia: MP3, WMA, MPEG4, MKV, JPEG
Stereo sound: yes
Sound power: 16 W (2 × 8 W)
Acoustics: two speakers
Interface: component, HDMI x2, USB, Ethernet (RJ-45), Bluetooth, Wi-Fi 802.11n, Miracast
Headphone jack: yes
TV weight: with stand: 7.5 kg
without stand: 7.4 kg
Dimensions: with stand 970x623x194 mm
without stand 970x568x76 mm
TCL L43S6400


General recommendations for TV LCD LED repair
Possible malfunctions

- TCL L43S6400 TV does not turn on at all. Control lamps do not light up or blink. The TV on the remote control and control panel buttons does not respond.

A fault in such cases should be looked for in the elements of the power source - the mains voltage converter (AC / DC), which is located on the main board MainBoard TPD.RT2841.PB772. Its output voltages should be measured, and in their absence, check the serviceability of the power switches (N-FET TO-220F) of the converters and rectifier diodes for the probability of a short circuit.
In case of any breakdowns in the secondary circuits, the converter can operate in an emergency mode of a short circuit, and with a short circuit in the power elements of the primary circuit, the mains fuse or the current sensor at the source of the key is often cut off.
The breakdown of power switches (MosFet) in switching sources is sometimes caused by malfunctions of other circuit elements, for example, in the circuits supplying the PWM controller, frequency setting or damper, as well as in the circuits of Negative Feedback (OOS) stabilization. PWM regulators (PWM) PWM SOT23-6, if they have no visible damage to the case and an open short circuit between the pins, are usually checked by replacing.

- There is no image, there is sound, it reacts to the remote control. Or the image may appear for a second when turned on and immediately disappear.

In some of these cases, the malfunction is caused by the lack of display backlighting. The reason can sometimes be in the power supply of the LEDs, but more often in their malfunction (breakdown or open circuit), sometimes in the violation of the contact connections of the LED strips.
To test the LED strips, in order to open all the transitions of the LEDs, several tens of volts or more are needed; it is best to use a current source for such purposes. The breakage of several PN junctions connected in series cannot be detected with a multimeter or tester. In such cases, it is necessary to open the panel and check each LED. If your multimeter cannot open the LED junctions in forward bias, you can sometimes detect the presence of a protective zener diode PN junction by connecting the probes in the opposite direction. If the zener diode is cut off or broken in K / Z, then the LED is faulty and requires replacement.

If TCL L43S6400 has no picture, but there is sound, often the LVW430NDEL display backlight simply does not work. Moreover, in LED TVs, the LEDs inside the panel usually fail, less often the LED driver.
In such cases, you can see a barely noticeable image when the ambient light hits the screen successfully.

Replacing the LEDs requires disassembling the LVW430NDEL LCD panel - a process that requires experience and qualifications from the master. We do not recommend doing such work on your own to owners of TVs and craftsmen who do not have experience in repairing LCD panels.

If there is no image, and the backlight is on, the screen becomes slightly lighter when turned on, and in an open TV, light is visible through the holes in the panel case.


In this case, the panel may also be faulty - damage to strips, loops, for example, as a result of moisture ingress after unsuccessful washing of the screen, the T-CON (Timing Controller) board may be faulty. But often the main board MainBoard TPD.RT2841.PB772 also turns out to be faulty, a software failure is also possible.
Then, first of all, you need to check the panel supply voltage, fuses on the T-CON board, as well as the supply and reference voltages of the column and line drivers - VGH, VGL, Vcom.
If these measurements are within the normal range, it is necessary to use an oscilloscope to trace the passage of LVDS signals from MainBoard TPD.RT2841.PB772, as well as synchronizing signals to loops with drivers.

Flooded or unsuccessfully washed screens of LED TVs can be restored, in about half of the cases, usually if significant damage has not formed in the loops and panel strips.

READ HOW TO REPAIR THE TV LED BACKLIGHT --------------> HERE.

- The indicator on the front panel blinks, the TV does not turn on in operating mode, does not respond to the remote control.

Repair or diagnostics of the TPD.RT2841.PB772 motherboard should begin with checking the stabilizers and power converters necessary to power the microcircuits and matrix. If necessary, you should update or replace the software (software). Repair of the board and replacement of EMMC: H26M41204HPR (8Gb) microcircuits are performed if the necessary equipment and the corresponding element base are available. Failures associated with the use of BGA soldering technologies can be localized by warming up.

Malfunction of the DVBT / T2 & SAT tuner is established after checking the software and all supply voltages at its outputs. The data exchange of the tuner with the processor via the I2C bus can be monitored with an oscilloscope.

Attention to users! Self-repair of the TCL L43S6400 TV without the appropriate qualifications and the necessary experience can lead to its complete non-repairability! 

 

Revision after repair of the backlight. Information from the master.

Decrease the backlight current from 280 mA to 190 mA - removed both 180 kOhm and 560 kOhm resistors and soldered one at 200 kOhm on pin 6 of the ISET driver MP3398E on the TPD.RT2841.PB772 board.
Driver current limitation. MP3398E. general information

To reduce the backlight current in LED drivers with an MP3398E controller, increase the resistance of the resistor from pin 6 (ISET) to the case. The maximum current in each channel (in milliamperes) for the resistor Rset (in kilo-ohms) is determined from the ratio ILed (mA) = 20362 / R (kOhm). 



DOWNLOAD  DIAGRAM  / PDF DATASHEET MANUAL  MP3398E  ------------------>    MP3398E

 

Additional MainBoard Repair

The appearance of the MainBoard TPD.RT2841.PB772 is shown in the figure below:





TPD.RT2841.PB772

Key features of the TCL L43S6400 device:

Installed matrix (LED panel) LVW430NDEL.
To power the backlight LEDs, a converter combined with the main board TPD.RT2841.PB772 is used, which is controlled by the MP3398E PWM controller. TO-252 switches are used as power elements of the LED driver.
The power module is combined with the MainBoard and is made according to the AC / DC flyback voltage converter using SOT23-6 PWM microcircuits and N-FET TO-220F power switches.
MainBoard - the main board (motherboard) is a TPD.RT2841.PB772 module, using EMMC chips: H26M41204HPR (8Gb) and others.
The DVBT / T2 & SAT tuner provides reception of television programs and tuning to channels.

 

PWM SMPS in SOT-23-6, SOT-26, TSOP-6 packages

In the circuitry of modern switching power supplies (SMPS), PWM controllers made in small-sized planar packages with six terminals have gained wide popularity. The enclosure type designation can be SOT-23-6, SOT-23-6L, SOT-26, TSOP-6, SSOT-6. The appearance and arrangement of the pins are shown in the figure below. In this case, the code marking LD7530A is shown on the left fragment of the picture.


 

 Pin assignment:
1 - GND. (Common wire).
2 - FB. (FeedBack - Feedback). Input for controlling the duration of pulses with a signal from the output voltage. Sometimes it can be labeled COMP (input comparator).
3 - RI / RT / CT / COMP / NC - Depending on the type of microcircuit, it can be used for a frequency-setting RC circuit (RI / RT / CT), or for organizing protection, as an input of a PWM trip comparator at a threshold value at its input, specified in the document. In some types of microcircuits, this input may not be used in any way (NC - No Connect).
4 - SENSE, otherwise CS (Current Sense) - Input from the current sensor at the source of the key.
5 - VCC - Input voltage supply and start of the microcircuit.
6 - OUT (GATE) - Output for controlling the gate (Gate) of the key.

Functionally, these regulators work on the principle of the previously popular xx384x PWM microcircuits, which have proven themselves well in terms of reliability and stability.

Some difficulties often arise when replacing or choosing an analog for such PWM regulators due to the use of code markings in the designation of the type of microcircuits. The situation is complicated by a large number of component manufacturers who do not always provide documentation to the mass access, just as not all manufacturers of finished devices supply repair service centers with diagrams, so repairmen often have to study real circuit solutions by installed components and wiring connections directly on the board.

In practice, PWM microcircuits and the marking code EAxxx and Eaxxx are often found. Official documentation for them was not found in the public domain, but discussions on the forums and pieces of pictures from PDF from System General, which publishes them as SG6848T and SG6848T2, have survived. The drawing is here placed left .


 

For the attention of the masters, here below are PDF datasheet tables compiled from information available on the Internet and PDF documents for the selection of analogues types when replacing the most common six-legged planar PWM with pinout pins: pin1 - GND, pin2 - FB (COMP), pin4 - Sense, pin5 - Vcc, pin6 - OUT ...
Their main difference is the application and purpose of pin 3. 

 

NamePart NumberFabricantMarking
SG6849SG684965TZFairchild / ON SemiBBxx
SG6849SG6849-65T, SG6849-65TZSystem GeneralMBxx EBxx
SGP400SGP400TZ System General AAKxx

 

 PWM controllers (PWM) with a 95-100 kOhm resistor on pin 3.

When applying the PWM listed below, the frequency should be set with the RT (RI) resistor from pin 3 to ground. Usually its nominal value is chosen 95-100 kOhm for a frequency of 65-100 KHz. For more details, see the here below attached documentation. PDF files are packed in RAR.

 

NamePart NumberFabricantMarking
AP3103AAP3103AKTR-G1Diodes IncorporatedGHL
AP8263AP8263E6R, A8263E6VRAiT SemiconductorS1xx
AT3263AT3263S6ATC Technology3263
CR6848CR6848SChip-Rail848H16
CR6850CR6850SChip-Rail850xx
CR6851CR6851SChip-Rail851xx
FAN6602RFAN6602RM6XFairchild / ON SemiACCxx
FS6830FS6830FirstSemi
GR8830GR8830CGGrenergy30xx
GR8836GR8836C, GR8836CGGrenergy36xx
H6849H6849NFHI-SINCERITY
H6850H6850NFHI-SINCERITY
HT2263HT2263MPHOT-CHIP63xxx
KP201
Kiwi Instruments
LD5530LD5530GL LD5530RLeadtrandxxt30 xxt30R
LD7531LD7531GL, LD7531PLLeadtrendxxP31
LD7531ALD7531AGLLeadtrendxxP31A
LD7535/ALD7535BL, LD7535GL, LD7535ABL, LD7535AGLLeadtrendxxP35-xxx35A
LD7550LD7550BL, LD7550ILLeadtrendxxP50
LD7550BLD7550BBL, LD7550BILLeadtrend xxP50B
LD7551LD7551BL/ILLeadtrendxxP51
LD7551CLD7551CGLLeadtrendxxP51C
NX1049XN1049TPXian-Innuovo49xxx
OB2262OB2262MPOn-Bright-Electronics62xx
OB2263OB2263MPOn-Bright-Electronics63xx
PT4201PT4201E23FPowtech4201
R7731R7731GE/PERichtek0Q=
R7731AR7731AGERichtekIDP=xx
SD4870SD4870TRSilan Microelectronics4870
SF1530SF1530LGTSiFirst30xxx
SG5701SG5701TZSystem GeneralAAExx
SG6848SG6848T, SG6848T1, SG6848TZ1, SG6848T2Fairchild / ON SemiAAHxx EAxxx
SG6858SG6858TZFairchild / ON SemiAAIxx
SG6859ASG6859ATZ, SG6859ATYFairchild / ON SemiAAJFxx
SG6859SG6859TZFairchild / ON SemiAAJMxx
SG6860SG6860TYFairchildAAQxx
SP6850SP6850S26RGSporton Lab850xx
SP6853SP6853S26RGB, SP6853S26RGSporton Lab853xx
SW2263SW2263MPSamWin
UC3863/GUC3863G-AG6-RUnisonic Technologies CoU863 U863G
XN1049XN1049, XN1049TPInnuovo Microelectronics49 xxx

 

 PWM controllers that use pin 3 differently.

When using the following PWM (PWM controllers), you should pay attention to pin 3, which can be used to organize protection - thermal or from overvoltage of the input voltage.
The frequency can be fixed at 65kHz, or set by the value of the capacitor at pin 3.
When replacing any microcircuits with analogs, carefully study the documentation. PDF files are packed in a RAR archive.

 

NamePart NumberFabricantMarking
AP3105/V/L/RAP3105KTR-G1, AP3105VKTR-G1, AP3105LKTR-G1, AP3105RKTR-G1Diodes IncorporatedGHN GHO GHP GHQ
AP3105NA/NV/NL/NRAP3105NAKTR-G1, AP3105NVKTR-G1, AP3105NLKTR-G1, AP3105NRKTR-G1Diodes IncorporatedGKN GKO GKP GKQ
AP3125A/V/L/RAP3125AKTR-G1, AP3125VKTR-G1, AP3125LKTR-G1, AP3125RKTR-G1Diodes IncorporatedGLS GLU GNB GNC
AP3125BAP3125BKTR-G1Diodes IncorporatedGLV
AP3125HA/HBAP3125HAKTR-G1, AP3125HBKTR-G1Diodes IncorporatedGNP GNQ
AP31261AP31261KTR-G1Diodes IncorporatedGPE
AP3127/HAP3127KTR-G1, AP3127HKTR-G1Diodes IncorporatedGPH GSH
AP3301AP3301K6TR-G1Diodes IncorporatedGTC
FAN6862FAN6862TYFairchild / ON SemiABDxx
FAN6863FAN6863TY, FAN6863LTY, FAN6863RTYFairchild / ON SemiABRxx
HT2273HT2273TPHOT-CHIP73xxx
LD7510/JLD7510GL, LD7510JGLLeadtrendxxP10 xxP10J
LD7530/ALD7530PL, LD7530GL, LD7530APL, LD7530AGLLeadtrendxxP30 xxxP30A
LD7532LD7532GLLeadtrendxxP32
LD7532ALD7532AGLLeadtrendxxP32A
LD7532HLD7532HGLLeadtrendxxP32H
LD7533LD7533GLLeadtrendxxP33
LD7536LD7536GLLeadtrendxxP36
LD7536RLD7536RGLLeadtrendxxP36R
LD7537RLD7537RGLLeadtrendxxP37R
LD7539C GLLD7539C GLLeadtrendxxP39C
ME8204ME8204M6GMicrOneME8204xx
NCP1250NCP1250ASN65T1G, NCP1250BSN65T1G, NCP1250ASN100T1G, NCP1250BSN100T1GON Semiconductor25xxxx
NCP1251NCP1251ASN65T1G, NCP1251BSN65T1G, NCP1251ASN100T1G, NCP1251BSN100T1GON Semiconductor5xxxxx
OB2273OB2273MPOn-Bright-Electronics73xx
R7735R7735AGE, R7735HGE, R7735GGE, R7735RGE, R7735LGERichtek
UC3873/GUC3873-AG6-R, UC3873G-AG6-RUnisonic TechnologiesU873 U873G

 


TV TCL L43S6400 with LCD LVW430NDEL, diagonal size 42.5 "(108 cm) 16: 9 format. The brightness of the screen, declared by the manufacturer, 270 cd / m2 is realized by LED backlight. Contrast - the ratio of maximum brightness to minimum, is not less than 4000 : 1. The LCD-panel of the TV is equipped with direct backlighting with LEDs - Direct LED.
The LVW430NDEL matrix and the MainBoard TPD.RT2841.PB772 software realize high-quality HD images at a resolution of 1920x1080 pixels in 1080p (Full HD) graphics. Image processing is implemented using modern High Dynamic Range (HDR) technology with an extended range of brightness gradations.
L43S6400 TV has built-in SMART software and preinstalled Android Operating System. Internet connection can be made via Wi-Fi wireless connection. Supported media file formats: MP3, WMA, MPEG4, MKV, JPEG.
Speaker power 16 W (2 × 8 W) is provided by two speakers. Uses the NICAM stereo signal processing system and the Sound Surround function.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), component, HDMI x2, USB, Ethernet (RJ-45), Bluetooth, Wi-Fi 802.11n, Miracast. A headphone output is provided. The digital tuner is capable of receiving television channels in the DVB-T, DVB-T2, DVB-C, DVB-S, DVB-S2 standards.

A power supply unit is used as part of the MainBoard.

Dimensions: with stand 970x623x194 mm, without stand 970x568x76 mm.

TV weight: with stand: 7.5 kg, without stand: 7.4 kg.

Attention! The LVW430NDEL panel of the TCL L43S6400 LED TV is an expensive and unreliable element.
Do not allow any impact on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it drips down the glass onto the cables to make the TV unrepairable. ...

REPAIRING / SERVICING TV TCL L55P65US

Technical description and composition of the TCL L55P65US TV, panel type and modules used. The composition of the modules.

TCL LED
Model: L55P65US

Chassis / Version: MS86R

Panel: LVU550NDEL

LED backlight: 4C-LB5506-HR1

LED driver (backlight): integrated into PSU

PWM LED driver: OB3365RP DIP-16

MOSFET LED driver: TO-252

Power Supply (PSU): L12NW 08-L12NWA2-PW200AA

PWM Power: PWM SOT23-6

MOSFET Power: TO-220

MainBoard: 40-MS86R1-MAA2HG

IC MainBoard: CPU: MSD6586PYET-8-00D9, eMMC: THGBMDG5D1LBAIL, SPI Flash: EN25Q32

Tuner: DVBT / T2 & SAT

Specifications L55P65US
TCL L55P65US
General recommendations for TV LCD LED repair
Possible malfunctions

- The TCL L55P65US TV does not turn on, does not respond to the remote control and control panel buttons, the indicators do not light up or flash.

With similar manifestations, in some cases, the L12NW power supply module is faulty. It is necessary to measure its output voltages, and if they are absent (full or partial), the serviceability of the power switches (TO-220) of the converters and rectifier diodes should be checked for a possible short circuit.
In case of any breakdowns of semiconductors in the secondary circuits, the converter can usually operate normally in an emergency short circuit mode. There are no output voltages. And with a short circuit in the power elements of the primary circuit, as a rule, the mains fuse breaks and, less often, the current sensor in the source of the key.
Mos-Fet power switches used in switching power supplies sometimes fail due to a malfunction of any other elements that can disable it in the key mode, or create an excess of the maximum permissible key parameters. These can be elements supplying a PWM regulator, frequency setting or damper circuits, or elements of negative feedback in the stabilization circuit. PWM controllers PWM SOT23-6, in the absence of visible damage or outright short circuits between the terminals, are checked by replacing them with new ones, or knowingly working properly.

- There is no image, the screen is black, there is sound, sometimes you can see barely noticeable outlines of the image in the ambient light of the screen.

Usually, in such cases, a malfunction is detected in the LED panel backlight nodes. Often the reason is a malfunction of the LEDs (open circuit, short circuit ...), or connectors of the strips (strings) 4C-LB5506-HR1, less often the LED driver is faulty.
It is impossible to detect an open circuit in the LED line without disassembling the panel with a simple multimeter. The LEDs are connected in series and a voltage of several tens of volts is required to open their junctions. Ideally, a current source is suitable for such purposes. You can open the panel and check each LED separately. Usually, Chinese multimeters lightly light up one 3-volt LED if you connect the probes to it in the forward direction (red probe to the anode, black to the cathode). For dual 6-volt LEDs, the PN junction of its emergency zener diode can serve as an indicator of the LED health. In the event of a malfunction of the LED, its zener diode will either be cut off or pierced in the K / Z.

If TCL L55P65US has no picture, but there is sound, often the LVU550NDEL display backlight simply does not work. Moreover, in LED TVs, the LEDs inside the panel usually fail, less often the LED driver.
In such cases, you can see a barely noticeable image with a successful hit of external light on the screen.

Replacing the LEDs requires disassembling the LVU550NDEL LCD panel - a process that requires experience and qualifications from the master. We do not recommend doing such work on your own to the owners of TVs and craftsmen who do not have experience in repairing LCD panels

If there is no image, and the backlight is on, the screen becomes slightly lighter when turned on, and in an open TV, light is visible through the holes in the panel case.
In this case, the panel may also be faulty - damage to strips, loops, for example, as a result of moisture ingress after unsuccessful washing of the screen, the T-CON (Timing Controller) board may be faulty. But often the main board MainBoard 40-MS86R1-MAA2HG also turns out to be faulty, a software failure is also possible.
Then, first of all, you need to check the panel supply voltage, the fuses on the T-CON board, as well as the supply and reference voltages of the column and line drivers - VGH, VGL, Vcom.
If these measurements are within the normal range, it is necessary to trace the passage of LVDS signals from MainBoard 40-MS86R1-MAA2HG with an oscilloscope, as well as synchronizing signals to loops with drivers.

Flooded or unsuccessfully washed screens of LED-TVs can be restored, in about half of the cases, usually if significant damage has not formed in the loops and panel strips. 


READ HOW TO REPAIR THE TV LED BACKLIGHT --------------> HERE.

- The indicator on the front panel blinks, the TV does not turn on in operating mode, does not respond to the remote control.

Repair or diagnostics of the 40-MS86R1-MAA2HG motherboard should begin with checking the stabilizers and power converters required to power the microcircuits and matrix. If necessary, you should update or replace the software (software). Often the MB (SSB) board needs to be replaced in the event of complex malfunctions that are difficult to detect. When trying to repair, you should check its elements - CPU: MSD6586PYET-8-00D9, eMMC: THGBMDG5D1LBAIL, SPI Flash: EN25Q32 and replace the failed chips with new ones. Some malfunctions can be associated with the use of BGA soldering technologies in modern Main Board. Typically, such defects are detected by local heating of the chip.

Malfunction of the DVBT / T2 & SAT tuner is established after checking the software and all supply voltages at its outputs. The data exchange of the tuner with the processor via the I2C bus can be monitored with an oscilloscope.

Users and owners of TVs should remember that attempts to self-repair the TCL L55P65US TV without the appropriate qualifications and the necessary experience can lead to serious negative consequences!

Revision after repair of the backlight. OB3365RP. Information from the master.

Reduce the backlight current from 90 mA to 40 mA - on pin 2 (I-SET) of the OB3365RP microcircuit, there are two 39 kOhm and 91 kOhm resistors in parallel in the L12NW power supply. Removed 91 kOhm.


Additional MainBoard Repair

The appearance of the MainBoard 40-MS86R1-MAA2HG is shown in the figure below:






40-MS86R1-MAA2HG

External view of the power supply:



 

 

 

 

 

 

PWM SMPS in SOT-23-6, SOT-26, TSOP-6 packages

In the circuitry of modern switching power supplies (SMPS), PWM controllers made in small-sized planar packages with six terminals have gained wide popularity. The enclosure type designation can be SOT-23-6, SOT-23-6L, SOT-26, TSOP-6, SSOT-6. The appearance and arrangement of the pins are shown in the figure below. In this case, the code marking LD7530A is shown on the left fragment of the picture.


 

 Pin assignment:
1 - GND. (Common wire).
2 - FB. (FeedBack - Feedback). Input for controlling the duration of pulses with a signal from the output voltage. Sometimes it can be labeled COMP (input comparator).
3 - RI / RT / CT / COMP / NC - Depending on the type of microcircuit, it can be used for a frequency-setting RC circuit (RI / RT / CT), or for organizing protection, as an input of a PWM trip comparator at a threshold value at its input, specified in the document. In some types of microcircuits, this input may not be used in any way (NC - No Connect).
4 - SENSE, otherwise CS (Current Sense) - Input from the current sensor at the source of the key.
5 - VCC - Input voltage supply and start of the microcircuit.
6 - OUT (GATE) - Output for controlling the gate (Gate) of the key.

Functionally, these regulators work on the principle of the previously popular xx384x PWM microcircuits, which have proven themselves well in terms of reliability and stability.

Some difficulties often arise when replacing or choosing an analog for such PWM regulators due to the use of code markings in the designation of the type of microcircuits. The situation is complicated by a large number of component manufacturers who do not always provide documentation to the mass access, just as not all manufacturers of finished devices supply repair service centers with diagrams, so repairmen often have to study real circuit solutions by installed components and wiring connections directly on the board.

In practice, PWM microcircuits and the marking code EAxxx and Eaxxx are often found. Official documentation for them was not found in the public domain, but discussions on the forums and pieces of pictures from PDF from System General, which publishes them as SG6848T and SG6848T2, have survived. The drawing is here placed left .


 

For the attention of the masters, here below are PDF datasheet tables compiled from information available on the Internet and PDF documents for the selection of analogues types when replacing the most common six-legged planar PWM with pinout pins: pin1 - GND, pin2 - FB (COMP), pin4 - Sense, pin5 - Vcc, pin6 - OUT ...
Their main difference is the application and purpose of pin 3. 

 

NamePart NumberFabricantMarking
SG6849SG684965TZFairchild / ON SemiBBxx
SG6849SG6849-65T, SG6849-65TZSystem GeneralMBxx EBxx
SGP400SGP400TZ System General AAKxx

 

 PWM controllers (PWM) with a 95-100 kOhm resistor on pin 3.

When applying the PWM listed below, the frequency should be set with the RT (RI) resistor from pin 3 to ground. Usually its nominal value is chosen 95-100 kOhm for a frequency of 65-100 KHz. For more details, see the here below attached documentation. PDF files are packed in RAR.

 

NamePart NumberFabricantMarking
AP3103AAP3103AKTR-G1Diodes IncorporatedGHL
AP8263AP8263E6R, A8263E6VRAiT SemiconductorS1xx
AT3263AT3263S6ATC Technology3263
CR6848CR6848SChip-Rail848H16
CR6850CR6850SChip-Rail850xx
CR6851CR6851SChip-Rail851xx
FAN6602RFAN6602RM6XFairchild / ON SemiACCxx
FS6830FS6830FirstSemi
GR8830GR8830CGGrenergy30xx
GR8836GR8836C, GR8836CGGrenergy36xx
H6849H6849NFHI-SINCERITY
H6850H6850NFHI-SINCERITY
HT2263HT2263MPHOT-CHIP63xxx
KP201
Kiwi Instruments
LD5530LD5530GL LD5530RLeadtrandxxt30 xxt30R
LD7531LD7531GL, LD7531PLLeadtrendxxP31
LD7531ALD7531AGLLeadtrendxxP31A
LD7535/ALD7535BL, LD7535GL, LD7535ABL, LD7535AGLLeadtrendxxP35-xxx35A
LD7550LD7550BL, LD7550ILLeadtrendxxP50
LD7550BLD7550BBL, LD7550BILLeadtrend xxP50B
LD7551LD7551BL/ILLeadtrendxxP51
LD7551CLD7551CGLLeadtrendxxP51C
NX1049XN1049TPXian-Innuovo49xxx
OB2262OB2262MPOn-Bright-Electronics62xx
OB2263OB2263MPOn-Bright-Electronics63xx
PT4201PT4201E23FPowtech4201
R7731R7731GE/PERichtek0Q=
R7731AR7731AGERichtekIDP=xx
SD4870SD4870TRSilan Microelectronics4870
SF1530SF1530LGTSiFirst30xxx
SG5701SG5701TZSystem GeneralAAExx
SG6848SG6848T, SG6848T1, SG6848TZ1, SG6848T2Fairchild / ON SemiAAHxx EAxxx
SG6858SG6858TZFairchild / ON SemiAAIxx
SG6859ASG6859ATZ, SG6859ATYFairchild / ON SemiAAJFxx
SG6859SG6859TZFairchild / ON SemiAAJMxx
SG6860SG6860TYFairchildAAQxx
SP6850SP6850S26RGSporton Lab850xx
SP6853SP6853S26RGB, SP6853S26RGSporton Lab853xx
SW2263SW2263MPSamWin
UC3863/GUC3863G-AG6-RUnisonic Technologies CoU863 U863G
XN1049XN1049, XN1049TPInnuovo Microelectronics49 xxx

 

 PWM controllers that use pin 3 differently.

When using the following PWM (PWM controllers), you should pay attention to pin 3, which can be used to organize protection - thermal or from overvoltage of the input voltage.
The frequency can be fixed at 65kHz, or set by the value of the capacitor at pin 3.
When replacing any microcircuits with analogs, carefully study the documentation. PDF files are packed in a RAR archive.

 

NamePart NumberFabricantMarking
AP3105/V/L/RAP3105KTR-G1, AP3105VKTR-G1, AP3105LKTR-G1, AP3105RKTR-G1Diodes IncorporatedGHN GHO GHP GHQ
AP3105NA/NV/NL/NRAP3105NAKTR-G1, AP3105NVKTR-G1, AP3105NLKTR-G1, AP3105NRKTR-G1Diodes IncorporatedGKN GKO GKP GKQ
AP3125A/V/L/RAP3125AKTR-G1, AP3125VKTR-G1, AP3125LKTR-G1, AP3125RKTR-G1Diodes IncorporatedGLS GLU GNB GNC
AP3125BAP3125BKTR-G1Diodes IncorporatedGLV
AP3125HA/HBAP3125HAKTR-G1, AP3125HBKTR-G1Diodes IncorporatedGNP GNQ
AP31261AP31261KTR-G1Diodes IncorporatedGPE
AP3127/HAP3127KTR-G1, AP3127HKTR-G1Diodes IncorporatedGPH GSH
AP3301AP3301K6TR-G1Diodes IncorporatedGTC
FAN6862FAN6862TYFairchild / ON SemiABDxx
FAN6863FAN6863TY, FAN6863LTY, FAN6863RTYFairchild / ON SemiABRxx
HT2273HT2273TPHOT-CHIP73xxx
LD7510/JLD7510GL, LD7510JGLLeadtrendxxP10 xxP10J
LD7530/ALD7530PL, LD7530GL, LD7530APL, LD7530AGLLeadtrendxxP30 xxxP30A
LD7532LD7532GLLeadtrendxxP32
LD7532ALD7532AGLLeadtrendxxP32A
LD7532HLD7532HGLLeadtrendxxP32H
LD7533LD7533GLLeadtrendxxP33
LD7536LD7536GLLeadtrendxxP36
LD7536RLD7536RGLLeadtrendxxP36R
LD7537RLD7537RGLLeadtrendxxP37R
LD7539C GLLD7539C GLLeadtrendxxP39C
ME8204ME8204M6GMicrOneME8204xx
NCP1250NCP1250ASN65T1G, NCP1250BSN65T1G, NCP1250ASN100T1G, NCP1250BSN100T1GON Semiconductor25xxxx
NCP1251NCP1251ASN65T1G, NCP1251BSN65T1G, NCP1251ASN100T1G, NCP1251BSN100T1GON Semiconductor5xxxxx
OB2273OB2273MPOn-Bright-Electronics73xx
R7735R7735AGE, R7735HGE, R7735GGE, R7735RGE, R7735LGERichtek
UC3873/GUC3873-AG6-R, UC3873G-AG6-RUnisonic TechnologiesU873 U873G

 

Key features of the TCL L55P65US device:

Installed matrix (LED panel) LVU550NDEL.
To power the backlight LEDs, a converter combined with a power supply is used, controlled by the OB3365RP DIP-16 PWM controller. TO-252 switches are used as power elements of the LED driver.
The formation of the necessary supply voltages for all nodes of the TCL L55P65US TV is carried out by the L12NW power module, or its analogs using PWM SOT23-6 microcircuits and TO-220 type power switches.
MainBoard - the main board (motherboard) is a 40-MS86R1-MAA2HG module, using CPU chips: MSD6586PYET-8-00D9, eMMC: THGBMDG5D1LBAIL, SPI Flash: EN25Q32 and others.
The DVBT / T2 & SAT tuner provides reception of television programs and tuning to channels.


TV TCL L55P65US with LCD LVU550NDEL, diagonal size 54.6 "(139 cm) 16: 9 format. The brightness of the screen, declared by the manufacturer, 270 cd / m2 is realized by LED backlight. Contrast - the ratio of maximum brightness to minimum , is not less than 4500: 1. The technology of manufacturing the screen of this TV model is realized with LED backlighting.
LVU550NDEL sensor and MainBoard 40-MS86R1-MAA2HG software realize high-quality UHD images at 3840x2160 pixels in 4K UHD, HDR standard. Image processing is implemented using modern High Dynamic Range (HDR) technology with an extended range of brightness gradations.
L55P65US TV has built-in SMART software and pre-installed Linux Operating System. Internet connection can be made via Wi-Fi wireless connection. Supported media file formats: MP3, WMA, MPEG4, HEVC (H.265), MKV, JPEG.
Speaker power 16 W (2x8 W) is provided by two speakers. Uses the NICAM stereo signal processing system and the Sound Surround function.
External interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, HDMI x2, USB, Ethernet (RJ-45), Wi-Fi. A headphone output is provided. The digital tuner is capable of receiving television channels in the DVB-T, DVB-T2, DVB-C, DVB-S, DVB-S2 standards.

The power supply is 08-L12NWA2-PW200AA.

Dimensions: with stand 1244x780x243 mm, without stand 1244x722x78 mm.

TV weight: with stand: 12 kg


 Attention! The LVU550NDEL panel of the TCL L55P65US LED TV is an expensive and unreliable element.
Do not allow any impact on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it drips down the glass onto the cables to make the TV unrepairable.

REPAIRING / SERVICING TV TCL LED32D3000

 Technical description and composition of the TCL LED32D3000 TV, panel type and modules used. The composition of the modules.

TCL LED
Model: LED32D3000

Chassis / Version: RD512V

Panel: LVW320NDEL

LED backlight: 32HR330M12A0

LED driver (backlight): integrated into MainBoard

PWM LED driver: MP3398A

MOSFET LED driver: TO-252

Power Supply (PSU): integrated into MainBoard

PWM Power: PWM SOT23-6

MOSFET Power: TO-252

MainBoard: TP.S512C.PB771

IC MainBoard: SPI Flash: 25Q64

Tuner: DVBT / T2 & SAT

Specifications LED32D3000
TCL LED32D3000
General recommendations for TV LCD LED repair
Possible malfunctions

- TV TCL LED32D3000 does not turn on and does not give any signs of turning on, does not respond to control buttons and to the remote control.

A malfunction in such cases should be looked for primarily in the circuit of a switching power supply (SMPS) - a converter (AC / DC) of the mains voltage, which is combined with the main board MainBoard TP.S512C.PB771 in this model. It is necessary to measure its secondary output voltages, and if they are absent, check the power switches (TO-252) and rectifier diodes in the converters for a short circuit.
In case of diode breakdowns in the secondary circuits, the converter can operate in an emergency mode of short circuit without output voltages, and with a short circuit in the power elements of the primary circuit, the mains fuse and / or the current sensor in the source of the key usually breaks off.
Breakdown of Mos-Fet keys used in switching power supplies is often caused by malfunctions of other elements, for example, in the power supply circuit of a PWM controller, in frequency setting or damper circuits, as well as in negative feedback stabilization. PWM microcircuits (PWM) PWM SOT23-6 are usually checked by replacing them with new ones, or knowingly working.

- There is no picture, but there is sound and reaction to the remote control. Or, for a second, the image may appear immediately after switching on.

The malfunction in most of such cases is found in the nodes and elements of the LED panel backlight. Often the reason is a malfunction of the LEDs (open circuit, short circuit ...), or the connectors of the strips (strings), less often the LED driver turns out to be faulty.
To check the LED strips for breakage without disassembling the panel, for example, a current source will help. It is impossible to open series-connected PN junctions with a simple multimeter; a voltage of the order of several tens of volts is required.

If TCL LED32D3000 has no image, but there is sound, often the LVW320NDEL display backlight simply does not work. Moreover, in LED TVs, the LEDs inside the panel usually fail, less often the LED driver.
In such cases, you can see a barely noticeable image with a successful hit of external light on the screen.

Replacing the LEDs requires disassembling the LVW320NDEL LCD panel - a process that requires experience and qualifications from the master. We do not recommend doing such work on your own to the owners of TVs and craftsmen who do not have experience in repairing LCD panels

If there is no image, and the backlight is on, the screen becomes slightly lighter when turned on, and in an open TV, light is visible through the holes in the panel case.
In this case, the panel may also be faulty - damage to strips, loops, for example, as a result of moisture ingress after unsuccessful washing of the screen, the T-CON (Timing Controller) board may be faulty. But the main board MainBoard TP.S512C.PB771 often turns out to be faulty, a software failure is also possible.
Then, first of all, you need to check the panel supply voltage, the fuses on the T-CON board, as well as the supply and reference voltages of the column and line drivers - VGH, VGL, Vcom.
If these measurements are within the normal range, it is necessary to trace the passage of LVDS signals from MainBoard TP.S512C.PB771 with an oscilloscope, as well as synchronizing signals to loops with drivers.

Flooded or unsuccessfully washed screens of LED-TVs can be restored, in about half of the cases, usually if significant damage has not formed in the loops and panel strips.


- The indicator on the front panel blinks, the TV does not turn on in operating mode, does not respond to the remote control.

Repair or diagnostics of the TP.S512C.PB771 motherboard should begin with checking the stabilizers and power converters necessary to power the microcircuits and matrix. If necessary, you should update or replace the software (software). Complex repair of MB (SSB) is possible only in a service center with the necessary equipment. Checking or replacing SPI Flash: 25Q64 requires the necessary training and professional skills to repair modules at the component level. Problems associated with the use of BGA soldering technologies can sometimes be diagnosed by the warm-up method.

If you suspect a malfunction of the DVBT / T2 & SAT tuner, first of all, you need to make sure that the software is correct, as well as the presence of the necessary levels of supply voltages and pulses of data exchange with the processor via the I2C bus on the corresponding terminals of the tuner.

Attention! Users and owners of LED32D3000 TVs who do not have the appropriate qualifications, knowledge and experience are strongly discouraged from trying to repair themselves in order to avoid negative consequences that can lead to the complete non-repairability of the device.


DOWNLOAD FIRMWARE FOR SPI FLASH  ----------->  TCL LED32D3000, Main: TP.S512C.PB771, Panel: LVW320NDEL.

 

Revision after repair of the backlight. MP3398A. Information from the master.

Decrease the backlight current from 300 mA to 200 mA - at the sixth pin (ISET) MP3398A replaced the 13 kOhm resistor in the photo by 20 kOhm.


Current limitation. MP3398A. General recommendations

To reduce the backlight current in LED drivers with the MP3398A controller, you should proportionally increase the total resistance of the resistors relative to the case at the ISET pin of the MP3398A controller. ISET (current setting) - pin 6 in SOIC-16 package (8 in SOIC-20 package).
The formula for the inverse proportion of the backlight current in milliamperes and the resistance Rset in kilo-ohms:
I [mA] = 988 / Rset [kOhm].

DOWNLOAD  DIAGRAM  / PDF MANUAL  MP3398A  ------------------>  MP3398A


READ HOW TO REPAIR THE TV LED BACKLIGHT --------------> HERE.

The appearance of the MainBoard TP.S512C.PB771 is shown in the figure below:




TP.S512C.PB771


The main features of the TCL LED32D3000 device:
Installed matrix (LED panel) LVW320NDEL.


To power the backlight LEDs, a converter combined with the TP.S512C.PB771 main board is used, controlled by the MP3398A PWM controller. TO-252 switches are used as power elements of the LED driver.
The power module is combined with the MainBoard and is made according to the AC / DC flyback voltage converter using PWM SOT23-6 microcircuits and TO-252 type power switches.

 

PWM SMPS in SOT-23-6, SOT-26, TSOP-6 packages

In the circuitry of modern switching power supplies (SMPS), PWM controllers made in small-sized planar packages with six terminals have gained wide popularity. The enclosure type designation can be SOT-23-6, SOT-23-6L, SOT-26, TSOP-6, SSOT-6. The appearance and arrangement of the pins are shown in the figure below. In this case, the code marking LD7530A is shown on the left fragment of the picture.


 

 Pin assignment:
1 - GND. (Common wire).
2 - FB. (FeedBack - Feedback). Input for controlling the duration of pulses with a signal from the output voltage. Sometimes it can be labeled COMP (input comparator).
3 - RI / RT / CT / COMP / NC - Depending on the type of microcircuit, it can be used for a frequency-setting RC circuit (RI / RT / CT), or for organizing protection, as an input of a PWM trip comparator at a threshold value at its input, specified in the document. In some types of microcircuits, this input may not be used in any way (NC - No Connect).
4 - SENSE, otherwise CS (Current Sense) - Input from the current sensor at the source of the key.
5 - VCC - Input voltage supply and start of the microcircuit.
6 - OUT (GATE) - Output for controlling the gate (Gate) of the key.

Functionally, these regulators work on the principle of the previously popular xx384x PWM microcircuits, which have proven themselves well in terms of reliability and stability.

Some difficulties often arise when replacing or choosing an analog for such PWM regulators due to the use of code markings in the designation of the type of microcircuits. The situation is complicated by a large number of component manufacturers who do not always provide documentation to the mass access, just as not all manufacturers of finished devices supply repair service centers with diagrams, so repairmen often have to study real circuit solutions by installed components and wiring connections directly on the board.

In practice, PWM microcircuits and the marking code EAxxx and Eaxxx are often found. Official documentation for them was not found in the public domain, but discussions on the forums and pieces of pictures from PDF from System General, which publishes them as SG6848T and SG6848T2, have survived. The drawing is here placed left .


 

For the attention of the masters, here below are PDF datasheet tables compiled from information available on the Internet and PDF documents for the selection of analogues types when replacing the most common six-legged planar PWM with pinout pins: pin1 - GND, pin2 - FB (COMP), pin4 - Sense, pin5 - Vcc, pin6 - OUT ...
Their main difference is the application and purpose of pin 3. 

 

NamePart NumberFabricantMarking
SG6849SG684965TZFairchild / ON SemiBBxx
SG6849SG6849-65T, SG6849-65TZSystem GeneralMBxx EBxx
SGP400SGP400TZ System General AAKxx

 

 PWM controllers (PWM) with a 95-100 kOhm resistor on pin 3.

When applying the PWM listed below, the frequency should be set with the RT (RI) resistor from pin 3 to ground. Usually its nominal value is chosen 95-100 kOhm for a frequency of 65-100 KHz. For more details, see the here below attached documentation. PDF files are packed in RAR.

 

NamePart NumberFabricantMarking
AP3103AAP3103AKTR-G1Diodes IncorporatedGHL
AP8263AP8263E6R, A8263E6VRAiT SemiconductorS1xx
AT3263AT3263S6ATC Technology3263
CR6848CR6848SChip-Rail848H16
CR6850CR6850SChip-Rail850xx
CR6851CR6851SChip-Rail851xx
FAN6602RFAN6602RM6XFairchild / ON SemiACCxx
FS6830FS6830FirstSemi
GR8830GR8830CGGrenergy30xx
GR8836GR8836C, GR8836CGGrenergy36xx
H6849H6849NFHI-SINCERITY
H6850H6850NFHI-SINCERITY
HT2263HT2263MPHOT-CHIP63xxx
KP201
Kiwi Instruments
LD5530LD5530GL LD5530RLeadtrandxxt30 xxt30R
LD7531LD7531GL, LD7531PLLeadtrendxxP31
LD7531ALD7531AGLLeadtrendxxP31A
LD7535/ALD7535BL, LD7535GL, LD7535ABL, LD7535AGLLeadtrendxxP35-xxx35A
LD7550LD7550BL, LD7550ILLeadtrendxxP50
LD7550BLD7550BBL, LD7550BILLeadtrend xxP50B
LD7551LD7551BL/ILLeadtrendxxP51
LD7551CLD7551CGLLeadtrendxxP51C
NX1049XN1049TPXian-Innuovo49xxx
OB2262OB2262MPOn-Bright-Electronics62xx
OB2263OB2263MPOn-Bright-Electronics63xx
PT4201PT4201E23FPowtech4201
R7731R7731GE/PERichtek0Q=
R7731AR7731AGERichtekIDP=xx
SD4870SD4870TRSilan Microelectronics4870
SF1530SF1530LGTSiFirst30xxx
SG5701SG5701TZSystem GeneralAAExx
SG6848SG6848T, SG6848T1, SG6848TZ1, SG6848T2Fairchild / ON SemiAAHxx EAxxx
SG6858SG6858TZFairchild / ON SemiAAIxx
SG6859ASG6859ATZ, SG6859ATYFairchild / ON SemiAAJFxx
SG6859SG6859TZFairchild / ON SemiAAJMxx
SG6860SG6860TYFairchildAAQxx
SP6850SP6850S26RGSporton Lab850xx
SP6853SP6853S26RGB, SP6853S26RGSporton Lab853xx
SW2263SW2263MPSamWin
UC3863/GUC3863G-AG6-RUnisonic Technologies CoU863 U863G
XN1049XN1049, XN1049TPInnuovo Microelectronics49 xxx

 

 PWM controllers that use pin 3 differently.

When using the following PWM (PWM controllers), you should pay attention to pin 3, which can be used to organize protection - thermal or from overvoltage of the input voltage.
The frequency can be fixed at 65kHz, or set by the value of the capacitor at pin 3.
When replacing any microcircuits with analogs, carefully study the documentation. PDF files are packed in a RAR archive.

 

NamePart NumberFabricantMarking
AP3105/V/L/RAP3105KTR-G1, AP3105VKTR-G1, AP3105LKTR-G1, AP3105RKTR-G1Diodes IncorporatedGHN GHO GHP GHQ
AP3105NA/NV/NL/NRAP3105NAKTR-G1, AP3105NVKTR-G1, AP3105NLKTR-G1, AP3105NRKTR-G1Diodes IncorporatedGKN GKO GKP GKQ
AP3125A/V/L/RAP3125AKTR-G1, AP3125VKTR-G1, AP3125LKTR-G1, AP3125RKTR-G1Diodes IncorporatedGLS GLU GNB GNC
AP3125BAP3125BKTR-G1Diodes IncorporatedGLV
AP3125HA/HBAP3125HAKTR-G1, AP3125HBKTR-G1Diodes IncorporatedGNP GNQ
AP31261AP31261KTR-G1Diodes IncorporatedGPE
AP3127/HAP3127KTR-G1, AP3127HKTR-G1Diodes IncorporatedGPH GSH
AP3301AP3301K6TR-G1Diodes IncorporatedGTC
FAN6862FAN6862TYFairchild / ON SemiABDxx
FAN6863FAN6863TY, FAN6863LTY, FAN6863RTYFairchild / ON SemiABRxx
HT2273HT2273TPHOT-CHIP73xxx
LD7510/JLD7510GL, LD7510JGLLeadtrendxxP10 xxP10J
LD7530/ALD7530PL, LD7530GL, LD7530APL, LD7530AGLLeadtrendxxP30 xxxP30A
LD7532LD7532GLLeadtrendxxP32
LD7532ALD7532AGLLeadtrendxxP32A
LD7532HLD7532HGLLeadtrendxxP32H
LD7533LD7533GLLeadtrendxxP33
LD7536LD7536GLLeadtrendxxP36
LD7536RLD7536RGLLeadtrendxxP36R
LD7537RLD7537RGLLeadtrendxxP37R
LD7539C GLLD7539C GLLeadtrendxxP39C
ME8204ME8204M6GMicrOneME8204xx
NCP1250NCP1250ASN65T1G, NCP1250BSN65T1G, NCP1250ASN100T1G, NCP1250BSN100T1GON Semiconductor25xxxx
NCP1251NCP1251ASN65T1G, NCP1251BSN65T1G, NCP1251ASN100T1G, NCP1251BSN100T1GON Semiconductor5xxxxx
OB2273OB2273MPOn-Bright-Electronics73xx
R7735R7735AGE, R7735HGE, R7735GGE, R7735RGE, R7735LGERichtek
UC3873/GUC3873-AG6-R, UC3873G-AG6-RUnisonic TechnologiesU873 U873G

 

 


MainBoard - the main board (motherboard) is a TP.S512C.PB771 module, using SPI Flash chips: 25Q64 and others.
The DVBT / T2 & SAT tuner provides reception of television programs and tuning to channels.
TCL LED32D3000 TV with LCD LVW320NDEL, diagonal size 32 "(81 cm) 16: 9 format. The brightness of the screen, declared by the manufacturer, 220 cd / m2 is realized by LED backlight. Contrast - the ratio of maximum brightness to minimum, is at least 3000 : 1. In the technology of manufacturing the screen of this TV model, LED backlighting is implemented.


LVW320NDEL panel and MainBoard TP.S512C.PB771 software realize HD image quality at 1366x768 pixels in 720p (HD Ready). Supported media file formats: MP3, MPEG4, MKV, JPEG.
The power of the acoustic system of sound is 10 W (2x5 W), provided by two speakers. Uses the NICAM stereo signal processing system and the Sound Surround function.


External interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, audio x2, component, VGA, HDMI x2, USB. A headphone output is provided. The digital tuner is capable of receiving television channels in the DVB-T, DVB-T2, DVB-C, DVB-S, DVB-S2 standards.

A power supply unit is used as part of the MainBoard.

Dimensions: with stand 732x483x173 mm, without stand 732x432x80 mm.

TV weight: with stand: 3.9 kg, without stand: 3.8 kg.

Attention! Panel LVW320NDEL LED TV TCL LED32D3000 is an expensive and unreliable element.
Do not allow any impact on the glass and pressure on the screen surface to avoid damage to the LED panel!
It is also unsafe for liquid to spill onto the screen. Sometimes one drop is enough if it drips down the glass onto the cables to make the TV unrepairable.