The best way is to inject a signal (I use a signal generator, but you can also use a looper pedal or any other way of putting a guitar-level signal) into the input and follow the signal path starting from the input and working your way towards the output using either an oscilloscope or an audio probe. If you don’t have either one, there are TONS of info on how to build yourself a very inexpensive audio probe. You then use the probe to follow the signal. When the signal disappears, you’ve isolated your FIRST problem. NEVER ASSUME ANYTHING. It is possible that there is more than one issue, but if you follow the signal with either scope or probe, you should be able to isolate the issue. If not, just keep asking questions – lots of help here.

Bud