Problem with panasonic TC-P50G20

[rdxblast]

Hi,

I have recentrly bought a used panasonic plasma model TC-P50G20. The TV was not working. The owner said I have to replace the power board and it should be fine. She also gave me the power board model number. Before I blindly buy the board and try to replace by myself, I tried to test whether thats the actual cause of the problem by looking into online info and this forum had great people and infos.

I am nowhere a electronics guy but I have a great attaction towards it. So, please forgive me if I am not aware of certain things or if I sound less informative about technical specs.

Here is a problem and I guess it was common problem:

I turned on the TV it has 4 led blinks. Then I disconnected the SC board wire which is plugged to power board. I turned on the TV which resulted in 7 blinks. As per my reading, I guess the problem maybe with SC board?

But, I found something awkward. Yesterday, when I tested I initially got 10 blinks and disconnected the SC board wire resulted in 7 blinks. Today, it turned out to 4(with original setup) and 7 (with disconnected SC board wire).

Is this something which I can fix cheaply without buying SC board?

Thanks in advance,
Rathna

[tom66]

Re: Problem with panasonic TC-P50G20

It sounds exactly like an SC board problem.
This failure is very common. tw2005 has a few repair successes with similar models:
https://www.badcaps.net/forum/showthread.php?t=22610

10 blinks is P board over-voltage on 15V, among others. This can occur if the SC has a short/leak from Vsus to 15V which will cause 15V to hit the OV threshold and shut down TV with SOS10.

[tw2005]

Re: Problem with panasonic TC-P50G20

10 blinks

Abnormalities of the F+15V.
 Reasons:
 The P board is not generating the F+15V
 SUB Voltages are affected by the K board or by
metal object present in the SD card slot..
Shorted Vsus (By the SS board or SC board).
Shorted Vda (By the panel, or any of the C board)
Wrong diagnostic by the A board.

Like Tom says, Whichever way you look at it, basically vsus will be dead short on the SC board. Classic failure for these I'm afraid. replacement Sc board and check the buffer boards for possible shorts.

SC can be repaired but not really a job for a beginner, involves replacing SMD components, shorted IGBTs, FET driver IC , etc. search TNPA5081 and you'll find my repair post.

rev AF,AP & AW will work in the TV

[everything]

Re: Problem with panasonic TC-P50G20

I don't want to make a new thread, anyone can get me headed in the right direction?

When you plug it in you get a double click, then about 14 seconds later another double click. Then I hit the power button, the green LED on the SC and SS boards light right up, then the red light on the lower part of the A board (this is looking at it from the back with the cover off and the room lights out) does a quick flash before the two clicks then the SS and SC board green LEDs fade out simultaneously, and we get the flash on the front LED which appears to be the single code flash, at first I was kind of thrown by that because it's a constant blink.

I got this from my sister and her husband, was on his wall the whole time he owned it. Here is how it failed. It would have problems powering up, took a few tries of hitting the power button over and over, and eventually then it quit powering up.

Any help to make this thing work again, I'd love to be able to watch Plasma screen. I'd like to throw my samsung series 5 520D LED 48 inch off the balcony.

Panasonic VIERA
TC-P50G20
SN LF00561057
Man. Feb 2010
TBLX0147

[tw2005]

Re: Problem with panasonic TC-P50G20

I don't want to make a new thread, anyone can get me headed in the right direction?

When you plug it in you get a double click, then about 14 seconds later another double click. Then I hit the power button, the green LED on the SC and SS boards light right up, then the red light on the lower part of the A board (this is looking at it from the back with the cover off and the room lights out) does a quick flash before the two clicks then the SS and SC board green LEDs fade out simultaneously, and we get the flash on the front LED which appears to be the single code flash, at first I was kind of thrown by that because it's a constant blink.

I got this from my sister and her husband, was on his wall the whole time he owned it. Here is how it failed. It would have problems powering up, took a few tries of hitting the power button over and over, and eventually then it quit powering up.

Any help to make this thing work again, I'd love to be able to watch Plasma screen. I'd like to throw my samsung series 5 520D LED 48 inch off the balcony.

Panasonic VIERA
TC-P50G20
SN LF00561057
Man. Feb 2010
TBLX0147

SOS 1 blink, Usually mainboard. Could be something as simple as corrupted data on an EEPROM or SPI chip. Options would be to get another main or send it into PTS Electronics or find someone if may have the files and try reflashing the 25 series SPI chip.

[everything]

Re: Problem with panasonic TC-P50G20

Thank you for the response, I did download the ZIP file for flashing the main board, doubt thats the same thing you mention, but maybe. I remember the days we used eeprom programmers. I found a new A board on the bay for $50 and ordered it up, double checking the suffix codes before they ship (I hope), if that matters. I guess for $50 why not give it a shot. I've watched to many youtube video's on this to where I'm feeling pretty pessimistic, but will keep my patience level on this project up as I learn more about the panasonic plasmas.