Guitar Effects Schematics

How do you troubleshoot a broken guitar pedal?

There appeared to be only one burnt out component and I replaced it but it still doesn’t work. it was the D1 diode that I replaced. It was broken (had burst) and there’s also a burn mark on the perf board. A near by wire was also singed but I replaced that. It did look like something was spilled inside the pedal and I’ve cleaned that out. When in bypass, the signal passing through is distorted and garbled, like hearing it on a faint radio station. But when the pedal is engaged, it doesn’t pass signal at all. I’m pretty certain that this is a copy of the Boss TR-2 because the schematic seems to fit with the exception of the IC chips.

http://www.schematicheaven.com/effects/boss_tr2_tremolo.pdf

Since the “bypass/engage mode” is triggered by a momentary switch, and the dry signal goes down a very processed chain of components, I haven’t been able to figure it out. What typically goes bad when there are spills? How would I go about figuring out where in the bad components are?

fix it?

Strange Devil Echo