REPAIRING AND NOT THROWING AWAY

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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..............The bitterness of poor quality is remembered long after the sweetness of todays funny gadgets low price has faded from memory........ . . . . . .....
Don't forget the past, the end of the world is upon us! Pretty soon it will all turn to dust!

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All posts are presented here for informative, historical and educative purposes as applicable within fair use. NOTHING HERE IS FOR SALE !

Wednesday 11 December 2019

LG 32 INCH LCD TV POWER BOARD EAY64548901 HOW TO TROUBLESHOOT



2018 UHD 720p LG LCD TV 32LK610BPUA POWER SUPPLY TESTING: Using a Simple 3V Jig or Smart TV Test Jig and Multi-Gender Board
32LK610BPUA SMPS (Power Supply) testing
The Smart Test Jig and Multi-Gender Board “Can” be used in this model for testing. Use Port P16. 13.2V Line does not have to be loaded in this case, Jig Switch set to 24V / LCD Power.

P801 To Panel Back-light Power pin 7.
P801 Pin 1 goes to Back-light Driver Q801 (Back of SMPS).
LED- (95.8V) 50%
LED+ (118.5V) 50%
AC 1st applied 168V (30sec) then fall to 76V During Stand-By LED+ will fluctuate 76V
Main Board Disconnected: 69V
Back-light Setting Dim 0% to Bright 100% Pins 2-6 are not connection.
Direct Lit Back-lights (8 LEDs on 1 Array Strip)
SMPS TEST: Forcing SMPS On.
This test requires simple 3V jig.
See below or Multi-Gender Board, use Port P16 (12pin),
Using 3V Simple Jig: Remove AC Power.
Disconnect P2300 on Main Board.
Test 1: Using a 3V jig, Jump 3V to pin 1 (PWR_ON).
Apply AC Power. (No Backlights in Test 1) (Pins 4-8) rises to 13.13V. Back-light Power LED+ 114.8V. LED- 95.6V. PDIM will be 3.42V.
Remove AC Power.
Test 2: Using a 3V jig, Jump 3V to pin 11 (DRV_ON).
Place a 12V Light Bulb on 13.2V to Gnd.
Apply AC Power. All Voltages should be produced.
(13.2V) 12.95V to Main and “LED+” 119.2V to the Back-lights), “LED-“ 94.3V.
This will also force the Backlights to come on. PDIM will be 3.77V.
Power Supply (SMPS) Board (EAY64548901)
P201 still inserted. P2300 removed.
Use P2300 side to insert needles from the Jig.
Note: STBY 7.83V (Pins 4-8)
Must be present when AC is applied before beginning test which indicates Standby voltage is OK.]
Special Note: The 13.2V Line “Must” be loaded using a 12V light Bulb when using the 3V Simple Jig).
3V SIMPLE JIG: Made from 2 (AA) batteries.
Jump + to – on one side.
On the other side, solder two red wires (needle tipped) to the + and one black wire (needle tipped) to the – side.  For Ground you can use Panel Back.
Voltages below for Back-light Power (LED+) are with Main disconnected and using Simple 3V Jig to supply turn-on commands on-at-a-time.
(Special Note: 13.2V Line “Must” be loaded using a 12V light Bulb when using the 3V Simple Jig).
(1) PWR-On Pin 1: Turns on 13.2V to the Main. No back-lights at this time. Back-light Power is 114.6V.
(2) MS (DRV_On) Pin 11: Turns on the Back-lights.
Back-light power goes to 119.3V.
Voltages given below for PDIM are with Main connected and receiving normal Digital Antenna Signal.
(3) PDIM Pin 12: Will vary according to incoming video IRE level and OSD Back-light setting Output from the Video Processor. And the Back-light settings in the Customer’s Menu 0% TO 100%. It is then routed out P1001 to P201 and sent to the LED Driver IC on the Back of the SMPS.
The Range is: Dim 0.17V ~ Bright 3.28V. (1.76V at 50%) PDIM is actually a 3.44V p/p pulse (PWM Control).
SMPS P/N: EAY64548901 components layout
Using Multi-Gender Board and Smart TV Test Jig
Power Supply Board Test 1 (Using 3V Simple Jig)
Note: The numbers in Fig 1 refer to the “Main” board connector (from the SMPS) that has been unplugged. Use this end for easy insertion of needles.
Count the Pins from the SMPS side.
AC “Must Not” be applied at any time while adding jumpers or while unplugging connectors, damage to the circuit Board may occur.
I) When AC is applied, the SMPS “MUST” be producing STBY 7.8V on pins 4-8, of P201. Note (If Main board is connected): When AC 1st applied, Back-light Power is 168V for 30sec. Then falls to 76V. (Main Disconnected: Back-light Power is 69V.
If STBY 7.80V is missing, STBY voltage may be loaded down by the Main Board or the Joy Stick/IR Board. Remove connector P2300 on Main board from SMPS.
If STBY is still missing, SMPS is defective but make sure AC is arriving at the connector SK100.
II) With P2300 on the Main Board unplugged, it will make insertion of the Needle tips easier. Use P2300 (Main Board side) to insert connections during these tests. Pin numbers will be given from P201 side.
TEST 1: TESTING THE POWER SUPPLY TURN-ON CIRCUIT. (See Fig)
No Back-lights during this test.
(1) Using two AA 1.5V batteries hooked in series (3V supply) jump the negative lead to ground (pin 3) [Main pin 9] and the positive lead to PWR-ON (pin 1)
[Main pin 11] as shown in example (A) in Fig.
Apply AC, this will turn on the SMPS. No Relay click will be heard.
Check that the 13.2V supplies that go to the Main board have turned on;
To Main Board Power:
• 13.2V: (P201 “13.12V” pins 4-8)
• Back-light Power will read 114.6V (No Back-lights)
(2) Remove AC Power (Leave Battery connected in this configuration).
Pin Numbers on Main are the same as pins on SMPS.
WARNING: Do not to let the leads touch positive (+) to negative (–) at any time as this will cause battery to overheat creating a fire hazard.
Power Supply Board Test 2
Continue if the 1st test was OK. Leave original jumper (A) in place. AC Power is removed at this time.
TEST 2: Back-light Section (Using P2300 side)
(3) (B) Jump the 3V to Pin 11 MS (DRV_ON). (See Fig )
Simulating a Power On and Back-light On command.
(4) (C) Add a 12V Light Bulb to the 13.2V Line and Ground.
(5) Apply AC Power.
Back-lights Normal: Back-light Power 119.3V
a) If normal, the back-lights will be on.
SMPS OK, Back-light Section OK. Back-light power P801 pin 7 (119.3V). Back-light Ground Return Pin 1: (94.3V)
Back-lights Abnormal:
a) Recheck all connections.
b) Confirm the PWR_ON and DRV_ON lines are pulling up to at least 3V.
c) Confirm Light Bulb isn’t open and connected to 13.2V line.
d) Check the connections to the Panel’s Back-lights.
If the DRV_On command is pulling up to 3V and the 142.8 is being Generated at P801, suspect a Panel’s Back-light Section problem.
Note: (Using Simple Jig), If P801 is disconnected (Back-lights Open), the back-light power will come on at 115.3V, and stay there.
(Main Connected), If P801 is disconnected (Back-lights Open), the back-light power will come on at 173V, and stay there.
Warning: Back-light Power is Slow to bleed down.
If test is successful, remove AC Power, Remove all Jumpers.
Reconnect P2300 on the Main and confirm PWR_ON and DRV_ON lines.
WARNING: Do not to let the leads touch positive (+) to negative (–) at any time as this will cause battery to overheat creating a fire hazard.
Pin Numbers on Main are the same as pins on SMPS.
Power Supply Board Voltage Reading during Test Modes
Note: With the Main board disconnected from the SMPS:
The Back-light Power is 69V.
(13.2V) is 7.83V in STBY (Main Disconnected).
Test 1 = PWR_ON only
Test 2 = PWR_ON and DRV_ON (13.2V Loaded with 12V Bulb)
Failure to use Light Bulb, Back-lights will Blink On/Off.
During Test, Main board is disconnected
BL = Back-lights.
Connector Voltage and Diode Check
P201 "SMPS Board" to "MAIN Board" P2300
PWR-On Pin 1: Turns on 13.2V to the Main.
Back-light Power is 114.8V, No back-lights at this time.
(2) MS (DRV_On) Pin 11: Turns on the Back-lights. Backlight power goes to 119.3V.
(3) P-DIM Pin 12: Will vary according to incoming video IRE level and OSD Back-light setting Output from the Video Processor. And the Back-light settings in the Customer’s Menu 0% TO 100%. It is then routed out P2300 to P201 and sent to the LED Driver IC on the Back of the SMPS.
Note: During STBY, LED+ is 76V. With Main disconnected 69V.
When AC 1st applied, LED+ is 168V (30sec) then fall to 76V.
Posted By: FRANK at 06:53
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