Debugging a good friends 80's Pro Co Rat

[mikemaddux]

So one of my good friends wants me to fix his rat and put a LED in....

The problem was:  pedal sounds fine bypassed, very very weak when effect is engaged

Ive got the 3pdt wired in and I get the same problem as before so I can assume that the switch was not the problem.
Ive tried the audio probe, and got nowhere quick.

I was moving my finger around in the area of the 2N5458 (is this for the millenium bypass?)  and the effect turned on but has no volume control.....

Any ideas?

[aron]

This is what I did. I took the entire board out of the box. I wired the board directly to the input/output jacks and then I plugged in. I measured voltages and verified that the board worked ok by itself. Then I rewired everything again.

With the audio probe, you listen to the input of the chip, the output and then trace through the pedal until you find the volume drop.

[mikemaddux]

What was the part that needed replacing?

[aron]

Someone had rewired using different pots/jacks. The board was shorting to the chassis, the input/output was mis-wired and oscillating. The entire pedal was a mess.