View Full Version : Panasonic 50" Plasma--no power and blinking LED


N2IXK
06-08-2015, 01:59 PM
Responded to a local Freecycle offer of a broken 50" Panasonic Viera plasma set (Model TH-50PZ850U), and hauled the beast home. Even got the remote with it! After setting it up on my dining room table (too big for the workbench in the shop!), I tried powering it up, and all that I get is a brief powerup (long enough to start the fans spinning), then shutdown and a repeated double blink from the power LED.

Suspecting that this was some kind of fault code, I did some Googling and found a service manual via ElectroTanya, and it turns out that the double blink indicates a problem with the +15V power rail. I also came across a LOT of folks with the exact same problem!

Following a suggestion I found on the AVS forums, I shot some freeze mist onto a little sub-module of the main "P" power board and tried starting the set again. Sure enough, It came right up! :D

There are 2 of the identical sub modules on the PCB (MC201 and MC301), and apparently these are a common enough failure point that there are ready-made repair kits to rebuild them, and a few folks offering rebuild services for these. Ordered a kit from a seller on eBay for ~$10 including shipping. The kit contains 2 SMPS controller ICs (NXP semiconductor TEA1611T) and 2 tiny (0602) ceramic 1 uF SMD caps. Playing around with my set and localizing the freeze mist a bit shows that it is actually the cap causing the issue in my set. Tacking in a regular leaded cap has the set working until the proper parts arrive in a couple days.

So it looks like I will have a nice "new" plasma set for the living room for $10 and a couple hours effort! :D

Eric H
06-08-2015, 02:39 PM
Good deal, I have the TH-50PZ85U, not sure what the differences are between the 85 and the 850U but the picture on the 85U is fantastic.
Mine has about 10,000 hours on it and still works fine, it's been relegated to a bedroom now so it doesn't get much use these days.

N2IXK
06-11-2015, 08:24 AM
Got the parts in yesterday, and installation went very smoothly. Set works great (let it burn in for about 3 hours), but am going to replace the 3 fans soon as one of them is a bit noisy (loose bearing). Found an eBay seller with NOS OEM fan assemblies complete with connectors, brackets and shock mounts attached for less than the raw fans were going for at DigiKey! They will just be a plug and play swap when they get here.

Now I have to get a new TV stand big enough to hold this beast....:)

Stromberg
07-15-2015, 03:22 PM
You certainly had better luck than me. Our TC-P50S30 died 3 months out of warranty, got 50% discount on repair via Panasonic. Two weeks ago dies again, I ordered and installed a new A main bd. Came to life enough to give 14 leds blinking code. Replaced P board no luck.

I sent the boards back for credit and will put the hulk at the curb soon. Less than 4 years old and sh_t the bed twice. Panasonic built crap in my opinion.

Enjoy your set I love those type of repair stories, I just didn't get that lucky.

Mike

rca2000
07-15-2015, 04:05 PM
Plasmas in general were NOT real reliable...hence...when they hav epretty much gone AWAY...

N2IXK
07-15-2015, 07:48 PM
Set is still working a month in. Was just the ticket for watching the Grateful Dead shows from Chicago on pay-per-view over the July 4th weekend. :thmbsp:

Hopefully will keep going for a while yet. Everyone who has seen it has remarked on the picture quality. Looks better than most of the LCD sets I have looked at in stores.