Panasonic TH42PD50U no power.

[mattpd]

Hello, I am hoping someone can help a beginner troubleshoot this TV. I already fixed the TV by replacing the P-board, but I want to get better at testing electronics and not swapping boards. So I now have this broken P-board and also a working P-board that I am able to test on. I would like to fix this broken board without referring to the working board because I am not always going to have this advantage.

Here is the background. Some "electricians" wired up my clients pool house with 120v and as soon as they flipped the breaker on the TV along with the stereo and refrigerator all turned off permanently. The TV has ZERO signs of life. No LED and no relay clicks. The working TV does click when you plug in AC, the broken board does not. I have checked a few things like the fuses, the ESR/capacitance of all electrolytic caps, and a lot of the "normal" diodes that I am able to test simply with my diode test meter. I was going to check the voltage on the filter cap and on the bridge rectifier, but those components don't get voltage until the TV switches ON, and the TV wont switch ON with the bad board. Where should I go from here?

[mattpd]

Re: Panasonic TH42PD50U no power.

Sorry to bump, but I'm still looking for any guidance. What could the relay click when you plug it in (or the lack of a click on the bad board) indicate?

[tom66]

Re: Panasonic TH42PD50U no power.

The lack of a relay click indicates there is no standby power whatsoever. That middle yellow transformer is probably the standby supply.

How did the electricians take normal 120V and manage to kill these devices? I would have thought the worst case would be no power or, perhaps fire or arcing from incorrect wiring.

[mattpd]

Re: Panasonic TH42PD50U no power.

Not sure what the electricians did, this was just the story I got from the TV owner. You think its a bad transformer or something before it? I'm waiting on a part to fix my blue ring tester so how should I test? Measure voltage coming off the transformer?

[tom66]

Re: Panasonic TH42PD50U no power.

Compare the diodes around it. There's usually also a small fuse near it - looks like one of these
http://www.goldmine-elec-products.co...es/G15798B.jpg

[wvgrbc]

Re: Panasonic TH42PD50U no power.

I’m new to the forum, I’ve searched – but need some guidance. I’m a novice at tv repair…. So let me get to the point and see if anyone can help.

I have an older Panasonic plasma th42pd50u 2006 model. The other day it just wouldn’t turn on. I have no standby power light and nothing happens when I push the power button or try to turn it on with the remote. I did some research and deduced that the main power board was the most likely issue. I replaced the board and have standby power (hear the audible click) when plugged in…..but still no LED light and nothing when I try to power turn on. I was afraid that the used power board might have been defective, but replaced the board again and still nothing. I’ve checked the fuses, all capacitors look fine – any ideas what might be causing this issue? Any help greatly appreciated.