8991XJ
Chief Journeyman
- Joined
- Oct 8, 2011
- Messages
- 1,299
Have a pair of monaural power amps with one having a couple 2W resistors dropping 2.7W while I wasn’t watching. Found this:
Burned board:
Doesn’t look bad, but the boys say that charred board can be conductive so the burn was scraped away:
The green dot pattern are the traces on the other side of the board. They were moved to allow repair
They were also thick enough to save them. The traces were pushed back into place and tape held them in place for the epoxy mixed with circuit board dust. This next photo shows slightly rough surface as this was my first board repair. I also reinstalled the tube socket
The component side which faces down in this amp was restored and shows a bit too much epoxy mix was used as it is a little higher than the board.
But you know? I just don’t care at all because this amp and the other in the pair sound great
And they look great. 50 watts each, cages not on the amps.
This repair is why I said remove burned stuff, clean, repair and repopulate in SirPaulGerman’s thread before I saw the need for extra cleaning because of the smoke and soot below the board.
Burned board:
Doesn’t look bad, but the boys say that charred board can be conductive so the burn was scraped away:
The green dot pattern are the traces on the other side of the board. They were moved to allow repair
They were also thick enough to save them. The traces were pushed back into place and tape held them in place for the epoxy mixed with circuit board dust. This next photo shows slightly rough surface as this was my first board repair. I also reinstalled the tube socket
The component side which faces down in this amp was restored and shows a bit too much epoxy mix was used as it is a little higher than the board.
But you know? I just don’t care at all because this amp and the other in the pair sound great
And they look great. 50 watts each, cages not on the amps.
This repair is why I said remove burned stuff, clean, repair and repopulate in SirPaulGerman’s thread before I saw the need for extra cleaning because of the smoke and soot below the board.