Panasonic Plasma TC-P50S1 missing 7/8 of picture.

[rickdw]

Does anyone have any suggestions on what to look at to narrow down the failed board or component of the above mentioned Panasonic plasma TV? I've attached a photograph of what is seen on the screen. Just a band across the top is working. The picture portion of what is shown looks fine. On screen menu etc. seems to look fine, at least what you can see of it. The rest of the screen is blank. Ignore the pixelization in the photo, it is just remnants of compressing the photograph.

There are no flashing diagnostic codes of the Power LED, and the green LEDs on the SC board (D16583) and SS board (D16253) are both on.

Thanks in advance.

[tw2005]

Re: Panasonic Plasma TC-P50S1 missing 7/8 of picture.

A little uncanny, yesterday.

https://www.badcaps.net/forum/showthread.php?t=48603

Hazard a guess maybe buffers or potentially SC. the G10 is related to this model i.e same gen,

I'd Do the usual cable checks, reseat maybe the sc to buffer leads, and maybe try getting into service mode and select test patterns in aging which will be tricky since you can't see the menu

reseat the ribbons at the A board

possibility of A board as well, that's a tough one.

[Andrew F. Ali]

Re: Panasonic Plasma TC-P50S1 missing 7/8 of picture.

I would say SD and SU boards.

[tom66]

Re: Panasonic Plasma TC-P50S1 missing 7/8 of picture.

I would say SU board. Possibly SD but unlikely.
The buffer data signal chains to each board, so if one IC goes bad the whole lot will go bad.

[rickdw]

Re: Panasonic Plasma TC-P50S1 missing 7/8 of picture.

Thanks for the suggestions. I re-seated the cables as suggested with no change.

The test points all down the SU and SD boards all have a similar signal trace on an oscilloscope. I've attached screenshots of the TPSC1 signal with a fully black screen and a white screen input into the HDMI input. The traces on the SD and SU boards all look similar to this, including the HV screw connectors.

Rick.

[tom66]

Re: Panasonic Plasma TC-P50S1 missing 7/8 of picture.

The period of interest is the portion just after the first reset wave (in 1st pic) - it should be around -180V then swing +140V above this negative DC portion for a SMALL portion of the wave (1/1080 to be exact for a 1080p panel), this is the ROW SELECT signal.
If the row select is missing, that portion will not light up.

[rickdw]

Re: Panasonic Plasma TC-P50S1 missing 7/8 of picture.

Excellent description, Thank-you. The -ve going row select on the first chip's test points look good, it is non-existent on subsequent test points. I guess that means I should go looking for an SU board.

[snake91876]

Re: Panasonic Plasma TC-P50S1 missing 7/8 of picture.

I got one I believe

[rickdw]

Re: Panasonic Plasma TC-P50S1 missing 7/8 of picture. - Fixed!

Thanks all. I was able to find an SU board at a local TV repair shop. This fixed the problem.

[tw2005]

Re: Panasonic Plasma TC-P50S1 missing 7/8 of picture. - Fixed!

Thanks all. I was able to find an SU board at a local TV repair shop. This fixed the problem.

Nice, I just learnt something.