Danelectro Dan-Echo pedal issue

[jackhammer]

my Dan-Echo has really weak delay sound output, I can hear it in the background if I listen very carefully, but there's no longer any gain, I've disassembled it to see if it's a simple continuity problem but nothing changed, any ideas of what might be wrong with it, or which component likely needs to be replaced?

[Kevin Mitchell]

I suggest you build an audio probe and trace the output signal back to the delay chip at pin 37. Try to find where the delayed signal is falling out. Work backwards to find the problem area.

Here's a copy of the schematic someone had shared in another thread. If you can follow it it'll prove to be useful debugging and navigating through the circuit.
Dan Echo Schematic

[Mark Hammer]

So it seems Q2 is being used as a voltage-controlled resistor, in much the same way that switching FETs are used.  The dry path is active always, and the "bypass" simply includes the delay/wet signal, or grounds it out via Q2.

I'd say the place to start your debugging is at the collector pin of Q2 (which is also the input to the Mix pot).  Another critical place to measure is at the base of Q2.  If there is an issue with the 4013 flip-flop, then that might compromise the switching.  Perhaps Q2 is sort of kind of "on", and constantly bleeding most of the delay signal to ground.