Panasonic TH42-PZ80U - SS board or Panel?

[coolie121]

Re: Panasonic TH42-PZ80U - SS board or Panel?

Scratch my last post. I stood behind it and waited. didn't take too long. The shut off interval seems to be getting successively shorter today. First 45 minutes, then 10, then 5, now 2.

The reading on TPSOS8 spiked as the TV shut off. It went from 0.02V to 23.6V

And the measurements in the previous post were made 30 seconds after the blinking started. It took me some time to get the multimeter and get in place.

[tom66]

Re: Panasonic TH42-PZ80U - SS board or Panel?

23V is quite high? Was that DC or AC?

But anyway, this indicates the SS or Panel is defective. I'd be more inclined to think SS, because I've not heard of an intermittent panel. I would try heating SS with hot air and seeing if it cuts off quicker.

[coolie121]

Re: Panasonic TH42-PZ80U - SS board or Panel?

DC voltage

This is strange. I changed the SS-board last week. I guess this means that my replacement from shopjimmy may have been dead on arrival . I will need to call them tomorrow.

By the way, what can cause a panel to go bad? And is there any way to fix them?

[tom66]

Re: Panasonic TH42-PZ80U - SS board or Panel?

Since you changed the SS, I would be more considering the panel then... though I just had a thought. If the D board stops sending signals to the SS, it can cause erroneous 8 blink codes. I have heard of this issue before, with the SC and erroneous 6/7 blink codes.

In terms of panel failure, this series of panels had a minor issue with contamination. It was (I think) Panasonic's 2nd or 3rd generation 1080p 42" plasma panel, which is a major process upgrade from doing 37"/42" 1024x768 panels and WVGA 853x480 ones. Some dirt or stray material gets trapped and migrates somehow, causing a shorted panel (SCn to SS electrode short.) As far as repairing it, I don't know -- but it might be possible to "blow out" a short by using a fairly high current. No idea if this would cause other damage though. And herein lies my confusion. If the panel was shorted, it should just not work at all. I don't know why it would be thermally sensitive, which is why I am considering the D board more or perhaps the A board.

Really the only way to be sure is start heating up stuff...

[coolie121]

Re: Panasonic TH42-PZ80U - SS board or Panel?

Then it looks like I'll be using the hair dryer this weekend when I've got time to tinker with the boards. I'll keep you posted. Thanks for the help so far everyone, I appreciate it.