Hello all,
Figured I'd jump into the world of component level repair with a Panasonic Plasma I found waiting to be trashed. To my surprise, everything is in perfect working order except the SN board. I would've been satisfied with sourcing the board and calling it a day, however it seems they're extremely hard (if not impossible) to find.
So here I am, with a decent reflow station and absolutely no idea what I'm doing. I've gone through all the threads on here, watched the shopjimmy tutorial, and determined what components are bad on the board.
This only left me with more questions, so before I botch an easy procedure and fry a potentially salvageable board, I figured I should summon the solder gods and ask them to show me the way.
Here are my questions, if anyone can shed some light on how I should go about this it'd be greatly appreciated!
1. The transistors and diodes Q401, Q402, Q421, Q422, D401, and D421 are showing dead shorts on my board. These are all included with the TNPA5349 repair kit. There are also four 7R5 resistors (R401, R402, R421, and R422) that are included as well. On my board, R401 and R402 are showing the correct resistance(7.5), but R421 and R422 are reading 6.5, is that within tolerance? Should I just replace all 4 resistors anyway?
2. I read a thread (not sure if it was on here) where the the poster had the same common failures on his board, along with transistor Q441. He claimed that when he replaced Q441, it restored function to the other components. Is that possible even though those transistors are showing dead shorts? Should I start with Q441 first?
3. Once I'm confident that I've got everything functioning on the board, is there a way to test it before I reconnect it? I'd hate to give it juice only for it to pop a second later because I missed something!
4. It's been said that the most common reason the board shorts out is because the ground screws/pads become loose causing arching. The ground screws were all snug on my board, could I be missing another underlying issue?
I have 14 blinks with the SN board connected, 7 blinks without it connected. With the SN board disconnected(ribbon cable as well), the main board and the SS board LEDs light up for a second, leading me to believe that they're both functioning correctly. I've checked those boards along with the power board and everything seems to be in order.
My apologies for the essay, I just want to make sure I've got everything covered. If I've given any incorrect information please feel free to correct me!
I'm just waiting on the components to arrive before I start butchering the board, so tell me how to do it right before it's too late!
Figured I'd jump into the world of component level repair with a Panasonic Plasma I found waiting to be trashed. To my surprise, everything is in perfect working order except the SN board. I would've been satisfied with sourcing the board and calling it a day, however it seems they're extremely hard (if not impossible) to find.
So here I am, with a decent reflow station and absolutely no idea what I'm doing. I've gone through all the threads on here, watched the shopjimmy tutorial, and determined what components are bad on the board.
This only left me with more questions, so before I botch an easy procedure and fry a potentially salvageable board, I figured I should summon the solder gods and ask them to show me the way.
Here are my questions, if anyone can shed some light on how I should go about this it'd be greatly appreciated!
1. The transistors and diodes Q401, Q402, Q421, Q422, D401, and D421 are showing dead shorts on my board. These are all included with the TNPA5349 repair kit. There are also four 7R5 resistors (R401, R402, R421, and R422) that are included as well. On my board, R401 and R402 are showing the correct resistance(7.5), but R421 and R422 are reading 6.5, is that within tolerance? Should I just replace all 4 resistors anyway?
2. I read a thread (not sure if it was on here) where the the poster had the same common failures on his board, along with transistor Q441. He claimed that when he replaced Q441, it restored function to the other components. Is that possible even though those transistors are showing dead shorts? Should I start with Q441 first?
3. Once I'm confident that I've got everything functioning on the board, is there a way to test it before I reconnect it? I'd hate to give it juice only for it to pop a second later because I missed something!
4. It's been said that the most common reason the board shorts out is because the ground screws/pads become loose causing arching. The ground screws were all snug on my board, could I be missing another underlying issue?
I have 14 blinks with the SN board connected, 7 blinks without it connected. With the SN board disconnected(ribbon cable as well), the main board and the SS board LEDs light up for a second, leading me to believe that they're both functioning correctly. I've checked those boards along with the power board and everything seems to be in order.
My apologies for the essay, I just want to make sure I've got everything covered. If I've given any incorrect information please feel free to correct me!
I'm just waiting on the components to arrive before I start butchering the board, so tell me how to do it right before it's too late!
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