Panasonic TC-P50X3 Totally DEAD

[muzicman61]

I have a 2 year old Panny TC-P50X3. After a nasty storm went through our neighborhood, and I believe the house may have been hit by lightning, the TV no longer powers on. At the same time, my cable modem fried and my DirecTV DVR. The Panny was on a surge protector and nothing else on that protector took a beating.

I get no blinking lights. I get no lights at all. I hear no sounds or clicks. So I figured perhaps it was the main power supply board. I have replaced that board but still I get nothing when I plug it in and try to turn it on.

I am relatively electronic savvy so I'm hoping there may still be a chance to repair it. My bedroom 37" Panny LCD is starting to have issues with the sound garbling and requires a power off to fix so I'd like to put this one in my bedroom.

Any thoughts?

Thanks,
Rob

[Caleb]

Re: Panasonic TC-P50X3 Totally DEAD

You will need a multimeter to test some voltages, Are you getting standby power to the A board? Does the main send the ps-on signal back to the p board? Surge could have come across the dvr to the A board. Pictures are always helpful. Service manual attached below

[tw2005]

Re: Panasonic TC-P50X3 Totally DEAD

probably entered the TV via the cable modem or DVR. My Panasonic and PVR were both on a UPS but the antenna system took a surge, destroy the masthead amp, killed the HDMI on the PVR and the HDMI on the TV A-board it was connected to. Very lucky the rest of the A-board survived minus 1 HDMI port.

[muzicman61]

Re: Panasonic TC-P50X3 Totally DEAD

You will need a multimeter to test some voltages, Are you getting standby power to the A board? Does the main send the ps-on signal back to the p board? Surge could have come across the dvr to the A board. Pictures are always helpful. Service manual attached below

Awesome. The service manual will be a big help. I'll do some reading and research and get back. Thanks for such a quick response.

[muzicman61]

Re: Panasonic TC-P50X3 Totally DEAD

probably entered the TV via the cable modem or DVR. My Panasonic and PVR were both on a UPS but the antenna system took a surge, destroy the masthead amp, killed the HDMI on the PVR and the HDMI on the TV A-board it was connected to. Very lucky the rest of the A-board survived minus 1 HDMI port.

Now that I think about it, you are spot on. It came in through the cable which explains why it took out the TV, Cable modem and DVR.

[muzicman61]

Re: Panasonic TC-P50X3 Totally DEAD

Well I dug out my trusty DVM and here's what I've found.

I am getting 120VAC to the board and across the fuses.

I get nothing out of the power supply board on any connectors (P11, P2).

Checked P6 from the A board (A6). Nothing on P1 (PANEL_MAIN_ON), P2 (P_S1), or P3 (P_S0).

Not sure if I got a bad replacement power supply or what at this point.

If pictures would be helpful I can take some, just not sure what specifically you want to see.

Thanks,
Rob

[Caleb]

Re: Panasonic TC-P50X3 Totally DEAD

According to the manual you should have +5v standby on pin 6 of the P6 to A6 connector, try it with the main unhooked in case it is shorting out. If you have +5v you can try to force on the power supply to see if everything else is ok. If no 5v then the power supply likely has a fault

[tw2005]

Re: Panasonic TC-P50X3 Totally DEAD

I'd be expecting this to be an A board fault, you won't see any voltages at those points until the A-board turns the rest of the PSU during normal startup.

Like caleb mentions, standby voltages should be there from the PSU.

2 power supplies , same result, nothing else on the surge protector blew but the cable modem and DVR both took a hit via the cable and I assume both those are connected to the TV via the A-board so I suspect the A-board got fried but the PSU will be ok.

[Caleb]

Re: Panasonic TC-P50X3 Totally DEAD

I was just reading this other thread from tom and it sounded similar enough you might want to give it a try on yours, his ac detect circuit is malfunctioning and is able to be brought to life with some freeze spray. Still think yours is likely the A, but this would be a easy test.

[westom]

Re: Panasonic TC-P50X3 Totally DEAD

Now that I think about it, you are spot on. It came in through the cable which explains why it took out the TV, Cable modem and DVR.

If it was incoming via a TV cable, then what was an outgoing path? If both do not exist, then no electricity and no damage.

Most common source of surge damage is, for example, a lightning strike to AC wires far down the street. That surge was incoming to every appliance. But not all appliances provide a best path to earth. Your TV cable (should) already has superior protection. But that same earth ground means a TV cable was a best outgoing path to earth. Incoming on AC mains to everything. Outgoing to earth via a TV cable. Damage is often on the outgoing path.

Damage also demonstrates how to avert future damage. That power strip only claims to protect from another type of surge that typically does not do damage. So damaged appliances on that power strip protected other attached appliances. To protect everything, one 'whole house' protector must connect low impedance (ie 'less than 10 feet') to the earth ground that already protects TV cable and telephone wires.

Once a surge was permitted inside, then it goes hunting for earth destructively. Damaged appliances connected that surge to earth - protecting all other appliances. Best protection means that surge is not inside the house. A solution that typically costs only about $1 per protected appliance.

BTW, another problem is called overstress. What was the incoming and outgoing path through that TV? Other parts in that path might be overstressed - fail months later. Another reason why surge damage is always a discussion of the incoming and outgoing current path.

[muzicman61]

Re: Panasonic TC-P50X3 Totally DEAD

Thanks for all the suggestions. Sorry for the delay in responding but I had a pretty big callmanager upgrade at work I had to attend to. I have finally been able to determine I am getting +5V to the A board on STB5 (A6 - pin 6). I have not been able to detect anything going back to the power supply on pin 1 (PANEL_MAIN_ON).

I was not quite able to follow the Tom66 thread about the AC detect. Is this MC Module on the A board or the P board?

I guess it is looking like the A board is toast but I have not for the life of me been able to find any in stock.

Thanks,
Rob

[tom66]

Re: Panasonic TC-P50X3 Totally DEAD

The AC detect post is not relevant to this set as the TV I'm working on is a 2008 model and yours is a 2011 model.

[muzicman61]

Re: Panasonic TC-P50X3 Totally DEAD

So is the general consensus the A board is bad? Anything else I can do to verify it's bad?

And does anyone know where I can find one of these? I've looked all over and everyone is either out of stock or wanting more for the board than I paid for the TV.

According to the manual the part number is TXN/A1PMUUS.

Thanks,
Rob

[ssuperman23]

Re: Panasonic TC-P50X3 Totally DEAD

Does anyone have the service tool settings for this TV ? I have messed mine up and now have a very bad picture . Mainly need the WB-ADJ settings but would be nice to have all to make sure there right too.

[Georgia088]

Re: Panasonic TC-P50X3 Totally DEAD

Hello. I see that this thread is old, but I am experiencing the same problem. Did the a board repair fix the problem or is it a power supply issue? Thanks!

[Kamranali]

Re: Panasonic TC-P50X3 Totally DEAD

Can any one help me how to fix the power supply p50x3 no standby volt