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Ask Shahid Your Own Question
Shahid, Technician
Category: TV
Satisfied Customers: 12458
Experience:  I have been repairing electronic gear since 1993 as a qualified Sony tech
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I have a Panasonic TX-P42S20B. It has stopped working and the

Customer Question

I have a Panasonic TX-P42S20B. It has stopped working and the light flashes four times. I cannot see any obvious signs of swollen capacitors. What tests can I try to figure out where the fault is? Many thanks
Submitted: 3 years ago.
Category: TV
Expert:  Shahid replied 3 years ago.
Hello, my name is Shahid, I'll be happy to assist you.
Please allow me to ask you a few questions to diagnose the problem.

- Have you tried to unplug TV power cord from wall outlet for 10 minutes to reset, replug and check?
If not yet, please try it and reply back how it goes.
- Also, do you have voltmeter to check volts on circuit board in TV?


Customer: replied 3 years ago.
Hello Shahid. Yes I have tried unplugging the power cord and left it unplugged for days. I do have a voltmeter.
Expert:  Shahid replied 3 years ago.

4 times flashing red light indicates Power Board issue as it might be missing some output volts.

Please check 15V, Vsus (approx 200V) F-15V supplies with voltmeter. TV would take few seconds to go to protection mode with flashing power light when push power button so need to take volts reading during that few seconds interval to verify the power supply board.

If volts are missing, please swap the power supply board to see what happens. We can't repair this board on component level so replacement of entire board is only option.

I trust my input will help you out. Please feel free to respond if you have any additional questions.
A positive rating to answer would be greatly appreciated, please click on smiley face under the answer then click submit button so I can get credit on website for my work.

Customer: replied 3 years ago.
Ok, I will check this out. If the volts are missing is it not possible to check the capacitors/ diodes etc to find which could be causing the fault and then I solder new components back on board?
Expert:  Shahid replied 3 years ago.

It is possible to test. check components if you have schematics of power board in hand but it will consume more time in trouble shooting and good money to get required component than swapping the whole board.

Customer: replied 3 years ago.
Hello Shahid. I cannot find a replacement power board for the TV, I can however find power boards for the Panasonic TXP42S20B. Do you have any way of obtaining information to find out if these boards will work on my tv? They look exactly the same apart from two additional capacitors. If not I am going to have to test the power board which I may need some help with.
Expert:  Shahid replied 3 years ago.

Can you please get me the part off of power board inside TV?

This will help me to compare the two boards.

Customer: replied 3 years ago.
The various part numbers are as follows:

Not sure which of these you need?
Many thanks
Expert:  Shahid replied 3 years ago.
LSEP1287 is the part number and few alphabets would be written ahead like LSEP1287behb etc

Please check above link to find out any identical power board there?

Customer: replied 3 years ago.
Hi. Yes it has the letters BE after it and unfortunately I can't find any. I have tried searching for all the various codes on circuit boards, even internationally. What components would be worth checking on the board for malfunction?
Expert:  Shahid replied 3 years ago.
OK, please check following link, is that power board identical to the board in your TV?