Panasonic Viera TH-P50U30A Plasma Faulty Panel?

[t4796]

I took a look at this plasma, it was flashing 7 blinks.

I disconnected the SU/SD boards from the SC and connected the appropriate jumper. It powered up with no blinks and I could hear audio/adjust volume etc when I connected an input source.

I powered it up with the gnd screws in place only and the jumper (and the ribbons to the panel) Anyway the screen lit up with the attached image. Can somebody in the know tell me if this means the panel is physically damaged?

It doesn't look like the photos I see on google images, but I'm prepared for the worst...

Maybe the 'Breaking News' I see on the panel is telling me something Would this be what was being displayed when it was damaged, how come it has this static image? There is no antenna or sources connected. Is this the last thing that was in the buffers? I don't understand how it works.

[tom66]

Re: Panasonic Viera TH-P50U30A Plasma Faulty Panel?

Panel is OK (plasma panel may do weird things when boards are not working), but I would not run this for too long, may further damage SN/SC board.

[t4796]

Re: Panasonic Viera TH-P50U30A Plasma Faulty Panel?

Thanks for the reply.

I will persist, and try to learn some more.

I see SJ has no stock of these older SU/SD boards, I found a pair of them from china. Is there anywhere else reputable. They are 5336AB, 5337AB.

If the blinking stops when I jumper the connector and remove those boards, do you think the SC board is safe to connect to new buffers?
I've seen some boards with heatsinks on them. I wonder if they would be any more robust than these ones, which seem prone to failure.

[t4796]

Re: Panasonic Viera TH-P50U30A Plasma Faulty Panel?

Only the SU board seems to be shorted on the output side.
SD board doesn't seem to have any shorts. I'll have to do some more tests though.

[t4796]

Re: Panasonic Viera TH-P50U30A Plasma Faulty Panel?

Just following up on this.

Replaced both the SD and SU with boards from the 3D model. The original was AB, the donor was AG.

Whilst it would run with only one board replaced, the other half of the screen had lines missing no matter how well seated the ribbons were.
With both boards replaced and ribbons seated runs fine. Fixed.

[tw2005]

Re: Panasonic Viera TH-P50U30A Plasma Faulty Panel?

Just following up on this.

Replaced both the SD and SU with boards from the 3D model. The original was AB, the donor was AG.

Whilst it would run with only one board replaced, the other half of the screen had lines missing no matter how well seated the ribbons were.
With both boards replaced and ribbons seated runs fine. Fixed.

Did you take the opportunity to change out or tighten the sc and ss board screws?

[t4796]

Re: Panasonic Viera TH-P50U30A Plasma Faulty Panel?

I tightened the SC screws but not the SS. Thanks for the heads up, I'll check them out.

I did notice some light damage on the underside near at the screw holes.

[tw2005]

Re: Panasonic Viera TH-P50U30A Plasma Faulty Panel?

Mainly the SC but any of those bolts that are where a soldered land is work loose. they're the wrong type, normally a philips pan head, spring washer and flat washer.

All historical now but did you try tightening those first and testing before heading off to the buffers?

If I'm reading correctly, you disconnected the buffers from the SC but left the Vfg bolts in , jumpered SC50 and powered on?

That's incorrect procedure, those bolts need to come out. I have a feeling someone blew their buffers doing that on this forum.

I'd advise not doing that. 7 blink traditionally you fully isolate the buffers, then jumper sc50 and if it passes check the buffers for shorts.

anyway you got it going which is good and parts are very hard to come by now.