Panasonic SC Board repair problem.

[Moreno83]

Hey guys ,

I need some help with repairing a TNPA5349.
I first used Norcal775 ( on youtube ) way of repairing the board using flux and a heatgun. Cleaned the board and reinstalled the IGBTS with flux. That ended with 4 or 5 bangs and almost all IGBTs and Diodes shorted. It scared the shit out of me haha.

I cleaned that board with acaton , might have shorted something? Aceton worked great with cleaning the board. I normally use 96% alcohol.

Anyways , i took another board with a 7 blink error and simply used the soldering iron , flux and 96% alcohol.
All went good and clean and turned the tv on. It stays on but i get this image on the screen. Distorted + half of screen is greyish
Its 100% a problem on the sc board but i cant find the problem and need some help.

I replaced q401/402/421/422 and the 4 resistors.
I also replaced ic502 and q531.

Are the buffers all gone or is this a voltage problem?



*I got a working SC board that works great in the same tv.

[Malachi]

Re: Panasonic SC Board repair problem.

I just got my repair kit from shopjimmy for this board. Now I'm scared to try it.

[Moreno83]

Re: Panasonic SC Board repair problem.

Nah don't worry , just use the instructions in this video.

https://www.youtube.com/watch?v=uIyHr13b5w8

I got 5 damaged SC boards that i got from a local tv shop. God knows what happened to them but im trying to repair them. Just seeking for advice as im almost there.
You probably just have shorted IGBT's , If not then try to see if you got shorted buffers. These boards had parts missing.

Don't only use the ground source for measuring buffers. There are small capacitors ( capacitor and diode , 3 or 4 of them ) close to the buffer chips. Use that as ground and measure the buffers , if you got a short then you know thats the problem. Took me a whole day to figure out my buffers were bad.

[Malachi]

Re: Panasonic SC Board repair problem.

I watched NorCal on replacing the IGBT's. I already removed the shorted ones with my heat gun. Was waiting for the parts to cum.
After reading your post, I'm trying to decide if I should use my soldering iron to put themes ones on or th heat gun.

[flocko]

Re: Panasonic SC Board repair problem.

You do not test buffers to ground?find test point VFG and test with meter set to low ohms run across all ribbon contacts any found low are defective

[Moreno83]

Re: Panasonic SC Board repair problem.

What do you mean Flocko? Check this video.

https://www.youtube.com/watch?v=51SZsfH60EY

[ReeceyBurger123]

Re: Panasonic SC Board repair problem.

Check the DG302 fet at the top it can also short some times and blow the board.

[Moreno83]

Re: Panasonic SC Board repair problem.

The board is not blown. It "works". All IGBTs and Diodes on THIS board are "fine". With fine i mean , its not measuring short.

By the way , its my very first time that i repair this particular board. This board on the pictures looked like a battlefield tbh.

Just removed the shorted parts. Looked for the missing parts as parts were missing. And cleaned up the board. Im already glad that it turns on , was a few hours work

[flocko]

Re: Panasonic SC Board repair problem.

All buffers ICs are tested to VFG (floating ground) you will find the test point on the SN board between Buffer IC4085 -IC4086