Access to bottom of PCB of JCM 800

[xtian]

I will eventually recap my 1983 JCM 800 2203 (I can hear a little note ghosting when cranked up). Replacing the multi-section cans will be no trouble, but I'm wondering about the pair of 10uF caps on the board. Do some leads need to be unsoldered to allow access to the underside of the board?

Anyone familiar with the procedure for replacing components on the PCB?

[martin manning]

My guess is detach the pots and input jacks from the front panel and then see what else you'd have to do (disconnect or detach) to tip the board up enough to gain acces to the underside.

[husky]

I will eventually recap my 1983 JCM 800 2203 (I can hear a little note ghosting when cranked up). Replacing the multi-section cans will be no trouble, but I'm wondering about the pair of 10uF caps on the board. Do some leads need to be unsoldered to allow access to the underside of the board?

Anyone familiar with the procedure for replacing components on the PCB?

Those are for bias, you need to remove all the wires on one or the other side, you might want to think about splicing them in from the top using the old leads unless you are doing this for someone else

[Jana]

I have worked on the bottom side of those PC boards without removing wires. I remove all the nuts from the pots and input jacks, remove the little nuts that mount the board and then gently tilt it all up. I block it up with whatever is handy and then carefully and gently work on the bottom with an inspection mirror, lots of light, hemostats and a long, thin soldering iron. Go slow and pretend it is brain surgery or you are defusing a bomb--everything slow and meticulous. I have done it many times.

[xtian]

I remove all the nuts from the pots and input jacks, remove the little nuts that mount the board and then gently tilt it all up.

I think that's going to work fine. Thanks!

[Gibsonman63]

I remove all the nuts from the pots and input jacks, remove the little nuts that mount the board and then gently tilt it all up.

I think that's going to work fine. Thanks!

Tedious, but it works. I find that painter's tape works well to keep the board flipped over so I can solder. If you press it right, the solder leads that go through the board will puncture through the tape and hold well, but remove easily. Then I use wooded door shims to keep things from shorting out while I am testing.

You really want to test before you put it back together so you don't have to take it back apart.

[xtian]

You really want to test before you put it back together so you don't have to take it back apart.

Ah! A wise man speaketh.

[Gibsonman63]

Thanks, but I had to learn that the hard way... more than once!