Panasonic P42VT30B fault - help to diagnose please.

[Jon_T78]

Hi, a friend has offered me his old plasma TV as he's sick of dealing with a fault it has and has since purchased a new one. I'm looking for advice on the potential to repair as I could make use of it and i hate the thought of it being thrown away.

The fault is that once turned on, it turns itself off after a few seconds, then comes back on again. Apparently it can do this for around 5 minutes and then settles with no issues - stays on and functions correctly. Upon turning on at the tv, the power LED turns green and flashes (green) very fast for around 5-6 seconds, then turns solid and the TV comes on (normal picture) after around another 5 seconds it turns off and repeats the green quick flashing light cycle for a further 5-6 seconds and comes back on.

I am a mechanical engineer, a keen DIY'er, and not afraid of some soldering. With the correct instruction I can diagnose if i know where to point my multimeter.

Just so you are aware, i downloaded the service manual and looked up the information about the self diagnostic - indicating whats wrong from the number of red flashing LED's, but as i dont see any flashing red LED's. I also read that this series of TV's were prone to bad ground points due to lose screws oholding down the boards, which resulted in transistors overheating.

Hope someday be can help me or point me to some resources on the internet.

Many thanks
Jon

[R_J]

Re: Panasonic P42VT30B fault - help to diagnose please.

It could very well be poor grounds under the screws. Remove the SC & SS boards and inspect the solder around the screw holes where it connects to the chassis. If it looks black like it was arcing, cleaqn the black corrosion, you can also resolder the rings around the screw holes. and reinstall the boards making sure the screws are tight. Or replace the screws with ones that have lock washers on them.
If they look like this, that could be the problem

Post some good quality pictures of the boards