Panasonic P50G20E

[Stanislav]

Hello boys
My TV Panasonic model -P50G20E stopped working, Flashes 8 times.
I bought from ebay SS Bord but no change blink again 8 times
I do not want to throw it is only two years,and worked less time.

Please for your help

[tw2005]

Re: Panasonic P50G20E

have not worked on an 8 blink yet but Check SS board

8 BLINKS.
Sustain Drive Circuit and Connection between the SS board and the Panel. Abnormality of the sustain drive circuit. Open or loose connection between the SS bd and FPCs from the panel (SS61, SS64, SS21,SS24, and SS58). Open or loose connection between connectors C10/C20 Wrong diagnostic by the A board Defective panel

SS , Panel , A

8 Blinks Error Code
The SOS Detect circuit in the Sustain board monitors:
��
Physical connection between the panel and the SS board.
��
The output of the sustain drive circuit.
Under normal condition, Q16280 is on. When Q16280 is on, a low is provided to the anode of D16280
D280).
If one of the FPC cables is open, Q16280 turns off and a high is provided to the anode of D16280 (D280).
This high is provided to pin 66 of the CPU in the A board. When this happens, the TV shuts down and the
power LED blinks 8 times.
If any abnormality occurs in the sustain drive circuit, a high is provided to the anode of D16255. This high is
provided to pin 66 of the CPU in the A board. When this happens, the TV shuts down and the power LED
blinks 8 times.
To determine if the 8 blinks is caused by the A board, SS board, or the Panel:
•
Isolate the SS board and check if the TV stays on when it's turned on.
•
If the TV does not stay on after disconnecting the SS board, the A board is defective.
•
If the TV stays on, then the SS or the Panel is defective.
•
If the anode of D16280 (D280) is high (2.7V) at the time the unit shuts down, the Panel might be defective. (Check for loose connection between the flex-cables and the SS board).
•
If the anode is low, the SS board is defective.

These 4 conditions can cause SOS8
1.
Abnormality of the Sustain drive circuit.
2.
Open or loose connection between the SS board and FPCs from the panel.
3.
When SC20, SC2, and SC10 are all disconnected.
4.
Wrong diagnostic by the A board

[Stanislav]

Re: Panasonic P50G20E

tw2005 Thanks for the reply

I did all the checks and the result is the following

1 . I checked all cable connections (SS61, SS64, SS21,SS24, and SS58) C10/C20 -OK

2 . I Isolate the SS board and TV stays on when it’s turned on for about one minute,and then turned OF and LED blinks 7 times

3 . In anode of D16280 (D280) http://store.picbg.net/pubpic/02/79/...5b10080279.JPG
When you turn off the TV Voltage is more than 5V ,and quickly reaches 0.1V The same happens when TV itself off

4. SC20, SC2, and SC10 -are correct switch

http://store.picbg.net/pubpic/0D/AB/...cc4f570dab.JPG

[Stanislav]

Re: Panasonic P50G20E

'll be glad to and others to share their opinion

In Bulgaria refused to repair my TV (or just do not know how) ,They want to replace all the boards without giving a guarantee that it will work. (This is stupid)

[Stanislav]

Re: Panasonic P50G20E

this is how the picture looks before TV going off.

[tom66]

Re: Panasonic P50G20E

That looks like a D-board failure to me.

[Stanislav]

Re: Panasonic P50G20E

Hello Tom
Who is board D ?
one more thing strange. If once off I run again ON ,So two or three times and the TV started working without any problems. If I turn off the TV after two minutes does not want to work

[tom66]

Re: Panasonic P50G20E

Ah, this model uses combined A and D board ("A" board or "AD" board); the particular board in question is the one with the video inputs on it.

[Stanislav]

Re: Panasonic P50G20E

I changed this board in red. but all the same

[tom66]

Re: Panasonic P50G20E

The board below it is suspect.

The SS board is likely OK; the AD board is misdiagnosing the problem as an SS board failure. (If it has problems with the processor, it can pick up incorrect error signals. Or, if the signals it sends to the SS board are not correct, it could cause the SS to output an error signal.)

You can try reflowing the AD board, as that can sometimes rectify odd issues like this.

[Stanislav]

Re: Panasonic P50G20E

Hi
Now come on AD - board, but there is some loss of signal

[tom66]

Re: Panasonic P50G20E

Reseat connector for that part of plasma panel -- on x-buffers.

Warning: Do NOT reseat them with power applied, you will destroy the plasma panel drivers. Be careful with them. They are not replaceable.

[Stanislav]

Re: Panasonic P50G20E

Hi Tom

I checked the connector
I think there is no signal from the new board because :

1. I put the old board and there is not disappears signal

2. with put new board (who came today) no signal in this part of the display.
I removed the connector of this section of the display and nothing will change

[tom66]

Re: Panasonic P50G20E

Well the good news is that it doesn't look like a panel defect to me. I've seen exactly the same when the panel connector is loose for one part:
https://www.youtube.com/watch?v=FXy2jHNpv_0&t=9m30s
(One part deliberately loosened, other part is faulty panel.)

So consider bad C board or bad AD board, did you just replace AD board or reflow it?

[Stanislav]

Re: Panasonic P50G20E

Can I check the signal to this jack does not work.?

but I doubt that this board works properly

AD board can it be reset?

[tom66]

Re: Panasonic P50G20E

Since you didn't get the issue with the old AD board, I would consider the new AD board to be defective.

SM: http://www.tgohome.com/ServiceManual...&Search=Submit

Factory reset as stated in the manual:
"Produce TV reception screen, and while pressing [VOLUME ( - )] button on the main unit, press [MENU] button on the remote control for more than 3 seconds."

[Stanislav]

Re: Panasonic P50G20E

Tom seller claims that there may be differences in service settings between the two boards ,and this is the cause of this defect
if there is some truth in this

[tom66]

Re: Panasonic P50G20E

That wouldn't cause a regional failure in the panel though. Maybe repeating patterns or lines or such. That is a simple defect in the AD board, C board or plasma panel. And you ruled out the C board and plasma panel by swapping the AD board.

Did you try the reset?

[Stanislav]

Re: Panasonic P50G20E

I can reset and update but no improvement.
when I'm in service mode I can not change anything (or I'm not in service mode)

[tom66]

Re: Panasonic P50G20E

Oh, that is service diagnostic -- my error. Checking the manual again:
"While pressing [VOLUME ( - )] button of the main unit, press [INFO] button of the remote control three times within 2 seconds."

That should be service mode.