Replacing caps and resistors... I screwed up

denisl · Post by **denisl** » Fri Nov 28, 2008 5:26 pm

Hi... It's been a while since I was asking advise how to fix my M44 and M50, well I finally got around to it and am now worried.

I replaced all the power caps and big DC caps as well as those resistors which looked like they got pretty hot. Of the 30 or so solder connections I made on the back of the board two of them look like absolute shit and I don't know what to do. I think I damaged the board.

The picture is embarassing.... Any advise to save my amps?

Post by **Wakeup** » Fri Nov 28, 2008 5:28 pm

Well unfortunately however embassing the picture may be, the picture might help us(not me...I dont know how to fix them...but others might) to be able to advise you how to fix it.

denisl · Post by **denisl** » Fri Nov 28, 2008 5:32 pm

sorry - pic is up.

GX3 · Post by **GX3** » Fri Nov 28, 2008 6:49 pm

In the pic just above the solder is that the PC board you can see??? is the joint solid or is it lose? the clear yellowish fluid is the flux from the solder not much to worry about there it can be cleaned off. Is there any way you can take a picture on a bit of an angle so we can see the side of the joint

yesterdaysyouth · Post by **yesterdaysyouth** » Fri Nov 28, 2008 7:15 pm

you lifted the pad on this side of the board that's why the solder didn't flow like it should. good news is that the electrical connection isn't on this side of the board, it is on the top side. just make sure the solder flow looks good on the top side and you will be fine...

a bit of rubbing acohol and a tooth brush will clean up the flux..

Thumper88 · Post by **Thumper88** » Fri Nov 28, 2008 7:23 pm

yesterdaysyouth wrote:you lifted the pad on this side of the board that's why the solder didn't flow like it should. good news is that the electrical connection isn't on this side of the board, it is on the top side. just make sure the solder flow looks good on the top side and you will be fine...

a bit of rubbing acohol and a tooth brush will clean up the flux..

not easy to do since I'm pretty sure that's a capacitor that's missing the pad...

MW3 · Post by **MW3** » Fri Nov 28, 2008 9:15 pm

Post more pics...

Maybe Roland can chime in.

He used to fix a few PG amps in his spare time.

denisl · Post by **denisl** » Sat Nov 29, 2008 9:15 am

OK - got more pics...

I don't think you can see from the top - but a pic of the top side of the new caps is below as well.

denisl · Post by **denisl** » Sat Dec 06, 2008 1:33 pm

anyone? Do I need to get the board reparied?

C - you out there?

Post by **Jacampb2** » Sat Dec 06, 2008 3:02 pm

The board should be repaired, but doing so may not be feasible... As stated above, the actual connection is on the top side of the board for those pads. If the solder flowed, then it hopefully took on the top side. Unfortunately, there is no way to check with caps, as they cover the top pads.

If you google PCB repair, there are a number of companies that sell kits and supplies to do repairs such as you need. There are also a number of companies that will do the work. I have no experience with these "kits" so I cannot attest to how well they work. There are also things out there for prototypers like tiny copper rivets, which can be used to put vias in a home made board, it is possible that you could find something like that that has a through hole made for repairs.

Good luck,
Jason