pdp42v18ha - Turns on, no picture, no response from buttons

[echodreamz]

Hello,

I have a pdp42v18ha (Viore) that powers up, the screen brightens enough to show it "works", I get some red sprinkles in the upper area of the TV. However the TV once powered on does not respond to input buttons, IE wont power off, wont change input, wont change channel, no menu etc. I have to pull the power to get it to turn off.

If I leave it on for ~20 minutes or so, I eventually get a bright blue picture (on channel 60). After another few minutes, the screen goes dark, I hear a relay click a few times and the process repeats.

I was told by a local repair shop that the main board is most likely bad (due to the TV not responding to button commands). Just trying to get some second opinions before I buy the board. I also removed the power to the sustain boards, the TV powers on, but I still cannot turn it off by the power button.

I checked all the caps on the board (visually), none are bulging or popped, they all look good.

Thank you all!

[lookimback]

Re: pdp42v18ha - Turns on, no picture, no response from buttons

Any luck with this? I have one doing the same thing. But, if I unplug mine, then plug it back in, it will work fine.

[goontron]

Re: pdp42v18ha - Turns on, no picture, no response from buttons

bad mainboard, in both cases.

[lookimback]

Re: pdp42v18ha - Turns on, no picture, no response from buttons

I was thinking that too. Could it be a bad MOSFET on the main? Or bad caps?

[goontron]

Re: pdp42v18ha - Turns on, no picture, no response from buttons

to me, it sounds like the BGA on the CPU has failed. reball or replace is the two ways to fix that. i could be wrong, budm might say something else.

[lookimback]

Re: pdp42v18ha - Turns on, no picture, no response from buttons

But if I unplug it, and plug it back in, it works fine. The issue only seems to appear if it's been off for several hours.

[lookimback]

Re: pdp42v18ha - Turns on, no picture, no response from buttons

I bought another TV from a guy 2 days ago, and he turned out to be the original owner of this one. Evidently I bought this from his cousin. Well, according to him, it's been doing this for a couple years.

[goontron]

Re: pdp42v18ha - Turns on, no picture, no response from buttons

^ in your case it may be dried up caps then.....

[lookimback]

Re: pdp42v18ha - Turns on, no picture, no response from buttons

I'll pull the main and check the caps for high ESR later.

[lookimback]

Re: pdp42v18ha - Turns on, no picture, no response from buttons

I'll try freeze spray on all the ICs when it's on. Maybe something isn't making contact when it's cold, but is OK after it's warmed up and expanded. I suppose that could be a BGA issue.

[lookimback]

Re: pdp42v18ha - Turns on, no picture, no response from buttons

Haven't had much time lately but I pulled the main board and did find 2 bad caps. Haven't checked the rest for high ESR yet.

[echodreamz]

Re: pdp42v18ha - Turns on, no picture, no response from buttons

Mine turned out to be a bad mainboard. $25 on ebay and walla TV came right up.

[lookimback]

Re: pdp42v18ha - Turns on, no picture, no response from buttons

I replaced those 2 bad caps and I think it's ok now. It comes right on without a problem. ESR on those 2 caps was 30Ω and 34Ω.

[lookimback]

Re: pdp42v18ha - Turns on, no picture, no response from buttons

Nope, not fixed. It works fine if I turn it on from the power button, but if I use the remote I get the little sparkles and the buttons become unresponsive. But also, once I unplug it, and plug it back in, then everything will work fine, including by remote. I think I should have recapped the entire board.