Panasonic TH-P50U30A SC Board TNPA5351 AF failure

[jeffecor]

Re: Panasonic TH-P50U30A SC Board TNPA5351 AF failure

I have a Fluke 115 and it was set on ohm m. I pulled all mosfets Q403,Q402, Q423,Q422 and the two diodes D401 and D421 tonight. I'm going to check the resistors. Tw2005 I was asking what was the finished ohm reading when the board was fixed. I know 2.784mohm means there is not a short that and the reading was after replaced the mosfets.

[tw2005]

Re: Panasonic TH-P50U30A SC Board TNPA5351 AF failure

I have a Fluke 115 and it was set on ohm m. I pulled all mosfets Q403,Q402, Q423,Q422 and the two diodes D401 and D421 tonight. I'm going to check the resistors. Tw2005 I was asking what was the finished ohm reading when the board was fixed. I know 2.784mohm means there is not a short that and the reading was after replaced the mosfets.

you did not write Mohm, hence my question. sounds about right, 3meg sticks in my mind

[jeffecor]

Re: Panasonic TH-P50U30A SC Board TNPA5351 AF failure

Sorry I didn't post it right. Just trying to fix the board and seen you and tom66 know a lot about these's board TNPA5351 as where its my first SC board like this setup.

[tw2005]

Re: Panasonic TH-P50U30A SC Board TNPA5351 AF failure

Sorry I didn't post it right. Just trying to fix the board and seen you and tom66 know a lot about these's board TNPA5351 as where its my first SC board like this setup.

I can only go with the info i read so I was unsure but sounds like it might be on track. I've done 1 of these boards and was very relieved and happy with just 4 igbts to get it going. I got more experience with thw 2010 5081 and they're never that easy.

hard to give 100% green light but if you've probed every smd igbt and diode and nothing else is shorted and those resistors are fine it might be worth the gamble.
Fet drivers are the only other things to watch for, not sure how to tell with these as they use different devices than in the past ( 8 pin I believe)

and those tiny 5 pinn smd transistors usually near those drivers (3Y)

[ricosavy]

Re: Panasonic TH-P50U30A SC Board TNPA5351 AF failure

Jeffcore did you get your board fixed?

[jeffecor]

Re: Panasonic TH-P50U30A SC Board TNPA5351 AF failure

Yes, same issues that are in the repair kit on jimmy. It was a one of the hardest to remove the mosfets and diodes but its working once again and hopeful sold too fixed the gounding pads too. I changed the voltage going to the boards to 213v and let the tv run for a week. I found a good board reads in the 5 ohms on the high voltage plug.

[tw2005]

Re: Panasonic TH-P50U30A SC Board TNPA5351 AF failure

I found a good board reads in the 5 ohms on the high voltage plug.

what do you mean? 5 ohms across SC2?

[jeffecor]

Re: Panasonic TH-P50U30A SC Board TNPA5351 AF failure

I don't know if it the 216v wires that plug into the SC board have a name, but put the mutlimeter in ohms and neg - to gound and + to the pins of the board one read should close to zero and one should get a ohm read around 5 is what I found.

[jeffecor]

Re: Panasonic TH-P50U30A SC Board TNPA5351 AF failure

https://www.youtube.com/watch?v=GFE14ElXz7g

samething I'm doing in the video

[Alastair E]

Re: Panasonic TH-P50U30A SC Board TNPA5351 AF failure

Err 5 ohm--Board has faults!

5 Meg-Ohm, prob board is OK....

Damned auto-ranging meters are a pain sometimes, and if you aint used to 'em can mis-lead.....

[tw2005]

Re: Panasonic TH-P50U30A SC Board TNPA5351 AF failure

approx 2800hrs and 1000 cycles since repaired, will be 2 years, in december