Panasonic TC-P50G20 bad SC board options

[Tom M]

My wife was watching TV the other night and heard a loud pop before the set went dark. When I investigated it was blinking 10 times. However after a power cycle it went to the 4 blink sequence.

After poking around on the forum I wound up here and did some more troubleshooting. With power removed, I disconnected the SC card and it went to 7 blinks so I thought I was on the right track. However I reconnected power to SC after a bit and the power on blink was now 10.

That said, it's clear what happened to the SC card based on looking at things. Q403 was blown completely apart and the broken bit was laying flat on the board as can be seen in the attached photo. Not sure if the darkening on the adjacent part is due to it overheating or a result of the catastrophic failure of Q403.

I guess the question is if am I better off buying a used SC board or buying a repair kit? I've got reasonable soldering skills but probably not enough to do a bunch of surface mount items. Though I guess the best route for those, if needed, would be to use solder paste.

Had the set since 2010 and it's been flawless so I hate the thought of going to a cheap LED panel if this one can be saved.

[Tom M]

Re: Panasonic TC-P50G20 bad SC board options

Is a Panasonic Repair Kit (TNPA5081) likely to solve the issue for me? I checked at the SC2 connector and it's not shorted so it seems like the issue may be limited to Q403.

Based on descriptions, some indicate the TNPA5081 kit includes Q403 and some do not so it's unclear if I should throw the $40 or so at it.

[budwich]

Re: Panasonic TC-P50G20 bad SC board options

Not sure how willing you are to go "offshore" (in terms of time frame and "ethics"), but I see SC cards for this model in the $50 range.

[Tom M]

Re: Panasonic TC-P50G20 bad SC board options

The cheapest I've seen are in the $70 plus $20 shipping. I've seen one for $87 & free shipping as well. Nothing as low as $50. Do you have a link you can share via PM?

If I just need to replace Q403 I'm up for that as nothing else seems blown but I'd hate to throw the $40 at it for a repair kit and it still not work as the rabbit hole can get deep pretty fast.

[budwich]

Re: Panasonic TC-P50G20 bad SC board options

what is your SC card? I was just looking "blindly" for the tv model. My "search" was with aliexpress. I had a panny 50s30 that blew some components of the SC. Tried to repair myself BUT unsuccessful, potentially because of "fake parts" (common problem with some parts / sites, along with "suspect work" (my soldering... :-)). I replaced the SC card for $100 ca and about 2-3 weeks ship time. I used "TNPA5081" in the search for your model and there appear to be lots of options for less than $50US on the site.

[Tom M]

Re: Panasonic TC-P50G20 bad SC board options

Mine's a TNPA5081AF.

I'll give aliexpress a look as I use them for computer supplies.

[Tom M]

Re: Panasonic TC-P50G20 bad SC board options

I got my board from aliexpress (it's an AY vs. my original AF) and I now get different behavior. No idea if the board rev is different enough to cause this or not.

AC Power applied -> Relay click -> ~10 seconds -> relay click

Power switch -> relay click - ~5 seconds -> panel on and immediately followed by -> panel off -> 6 flashes

Disconnect SC2 and get 7 flashes

Based on the troubleshooting blink codes it looks like I've got a bad SC board from aliexpress.

Other than working with the vendor for a refund what should the next steps be? I guess I could order a repair kit and try to fix my original board but I prefer to not just throw money at it in blind fixes if i can avoid it.

Well, reading though most of 23 pages on another thread it appears the AY version is for the 3D and not my 2D. Though the vendor is saying that the AY board will work fine.

[Biruslapio]

Re: Panasonic TC-P50G20 bad SC board options

I had this same experience adapting a TNPA5081AY from a P50VT20B(3D) to a TNPA5081AF P50V20B(not 3D), installed the board, panel flashed and 6 blinks.

There's a handful of components that differ between the boards, incluing a VHIZ_GEN voltage section that is present on AF but missing on AY, even after I replaced everything it was still flashing, after disconnecting and reconnecting SC board the TV powered up and worked fine, don't know exactly what was wrong and even if it was necessary to convert AY>AF, but it is doable.

To convert AY to AF you need a hot air station and some experience with SMD soldering.

[Tom M]

Re: Panasonic TC-P50G20 bad SC board options

Thanks for the info. I don't have that type of equipment handy so probably not going to happen from my end so hopefully the vendor will do a refund.

Still chatting with them before opening a dispute. For all the good that will do.

[budwich]

Re: Panasonic TC-P50G20 bad SC board options

:-( sorry to hear about this trouble with the replacement board... I guess I should have kept my post to myself. Hopefully, they will refund the amount. Related, I too did not buy the exact replacement board for my set BUT an "earlier version" (based alphabet). I did compare all the components of the different version and found only changes is missing / added capacitors in a few places. Of course, the 3d versus 2d is probably a completely different "animal" as suggested previously. Anyway, hopefully it will work out.

[Tom M]

Re: Panasonic TC-P50G20 bad SC board options

Hey, you definitely should not feel that way.

There were a couple of places to choose from and I did what I felt was due diligence. The good news is that it's not a ton of $$$ so we'll just see how this plays out.

Worst case is I drop the bucks on the repair kit and try and fix my old board.

If that then fails I have the hard decision of spend limited money on a short term replacement LED set as this is the wife's and she's not fussy about image fidelity. The other option is to step up and get a newer 65 inch OLED set for the media room and move my 58" Panny into the bonus room to replace the 50".

[Tom M]

Re: Panasonic TC-P50G20 bad SC board options

Well, I purchased one of the repair kits for the TNPA5081AF and installed it. Using a microscope, everything looked good visually so I installed the board and plugged in the set. Heard the clicks and no flashing SOS. Based on that I then hit the power button on the set and a few moments later Q660 blew with a very loud pop as the magic smoke wafted through the air.

Looks like I'm back to the hard decision point. I may look for a replacement board again and hopefully will get an AF version this time instead of an AY. I'd also be up for modding the AY board to an AF but it sounds like that may be too much effort.