Panasonic TH-50PX80 killed by lightning strike, help me save her!

[SluggerB]

You need to do testing, remove powerboard, check the underside for anything obvious. here's a few things to check Q151, Q171, D601, D602, D603, D607, D615, youtube is your friend for testing procedures if needed.

I checked the back of the power board (and the front, and both sides of the main board) under magnification and nothing is obviously broken. Both boards look pristine. I could randomly check components but I dont't know what the correct values are. The only thing I have found that I know if incorrect is the standby voltage should be 5v and it is not.

[nomoresonys]

Forget voltages for now, check those components, tv unplugged from power. Just do a quick check and see if any of the transistors which are labeled starting with a Q, have any of the three pins shorted to each other as meter probes on pin 1 and 2, 1 and 3, 2 and 3, and just check the diodes in diode mode.

[nomoresonys]

A bit of testing there: https://www.youtube.com/watch?v=i4jTHhXuKLA

[nomoresonys]

And there: https://www.youtube.com/watch?v=qhPZD9avoac

[nomoresonys]

What may have happened, did to me once. A strike nearby borked the firmware, fixed with a firmware update with a usb drive. Being old you may not be able to find the firmware tho.

[SluggerB]

Update: I found a better service manual for the TV, which pointed out where to test for th STB voltage, and it IS present on the power board.

I put the old main board back in and it did what it always did.

• With the original main board in, when you turn the TV on, it turns on, the power light stays steady, there is no picture. It will just sit like this.
• With the new main board in, when you turn the TV on, after a few seconds, it goes into an "SOS" mode, turns itself off, and gives a single blink. According to this manual, one blink means "Communication Error with Microcomputer". The manual gives no other info besides this on that error, other than the source of that error is on the main board itself, not the power board

Did I get a bad main board off eBay? It at least detects what is going on enough to go into it;s safety mode but the blink code seems to indicate the new board is faulty.

[SluggerB]

I might have found the issue... I might have bought the wrong main board off eBay

My original has a model number of TNPH07163A. The one they sent me was TNPH0716ABS. They look identical and seem to have the same chips on them, but perhaps they have different firmware or software?
So my assumption now is that my power board is fine, it was my main board that got damaged, the main board I was sent is fine, but it's the wrong one for my TV, because of that it triggers the SOS condition and gives the single red light blink indicating an issue with the main board.

I ordered the correct one from another seller, and it's a new old stock unit not even used, so back to the "waiting for shipping" game.

[lotas]

Check...

[SluggerB]

So I have just learned about the beauty of Panasonic "Suffix's"

My dead board is an AH suffix. The replacement board I ordered is an AB suffix. These are indicated by a resistor on the board on a bank of spots a resistor could go

If I moved the resistor on the new board from AB to AH, would it work?

[SluggerB]

Well after all the waiting, the correct main board I ordered off eBay finally showed up. I opened the box all excited ... and the box didn't even have a main board in it, it was a power board to a completely different TV. So that's going back.

I may have tracked down a store that has one but they are being hilariously unresponsive. I'm also fed up with this mess and am going to go looking at new TV's this weekend. I would like to fix this one but I'm sick of waiting weeks for parts to ship only to show up and be the wrong part.

[nomoresonys]

I think you're on the right path now, R.I.P. to those old heavy 720p dinosaurs.

[CapLeaker]

Many years ago I had repaired the similar issue on a lightning struck Panasonic. It would turn on for a split second and then turn off. It was the HDMI IC that was shorted and got hot fast.

[SluggerB]

New main board shows up today. I am 99% sure it is the right version and right suffix. Assuming the seller's listing was correct, hopefully that gets her going again

[Davi.p]

Hi, the kind faulty part is a standby memory, that is somewhere on the main board, you posted a very undecent picture, can you post a good one following directions in my sticky post ? it is maybe the 14pin ic, but have you got a simple eprom writer? Need to find the dump too... PS: the memory could be erased by electro magnetic waves of the lightning, thus wireless, this is kindly what happened...

[SluggerB]

Hi, the kind faulty part is a standby memory, that is somewhere on the main board, you posted a very undecent picture, can you post a good one following directions in my sticky post ? it is maybe the 14pin ic, but have you got a simple eprom writer? Need to find the dump too... PS: the memory could be erased by electro magnetic waves of the lightning, thus wireless, this is kindly what happened...

I've heard a few people saying the EM from the lightning could be the culprit, which is interesting. I do not have an eeprom writer, and even if I did the firmware is not online anymore. I've been looking

Either way it's a moot point, the new board showed up, it's the correct suffix version, I put it in the TV, and it's working again just fine. And it was only $46. I returned the other boards. Case closed.