Debug crybaby, veeeery faint.

[Hotstuff]

Hello everybody

I've been trying to get this stock gcb-95 crybaby back to life but sadly no success.

The bypass works but switched on there is no sound, or very little. If I crank up the volume on my amp I get some signal on which I do hear a wah effect.

Here are my measurements on the transistors.
Q1: mpsa13
c: 8.59v
b: 4.26v
e: 3.54v

Q2: mpsa18
c: 4.63
b: 0.665
e: 0.07

Q3: mpsa18
c: 8.21
b: 4.18
e: 3.75

help much appreciated!

[jasperoosthoek]

The voltages around Q2 are to blame. The emitter voltage is way too low. It should be roughly around 1 volts.

Looks like something shorts the emitter to ground. Q2 itself is probably still ok as the rest of the voltages are normal if the emitter is shorted to the ground.

I take that Q1 is the buffer, Q2 the first stage connecting it's collector to the output and Q3 is the feedback transistor.

So that means that only the 470 ohms resistor of Q2 could be to blame or there is a short somewhere.