Vintage Fender Fuzz/Wah... Dead Fuzz...

[1WoodHippie]

This one is driving me crazy. It's gotta be something obvious that I'm over looking...

On the bench is a vintage Fender Fuzz Wah pedal. Wah and Volume work great. Hit the Fuzz and it shuts down totally. After doing some signal tracing I found one of the Zeeners on the output shorted to ground so I replaced both of them. Also found that Q2 was bad so I replaced it with a 2n3904. (had to swap a couple legs to get the pinouts to work, but it should work. But now, it's still dead.

I'm doing signal traces with an ipod and a listener box and I can get a good solid signal up to the base of Q2, then it just progressively diminishes in volume as it goes to the output.

Anyone got any ideas/thoughts??

thanks in advance.

[Enzo]

What was the original transistor type? I have no problem with 2N3904, but I would be suspicious of the having to rearrange the legs. ANy time we do that we have the potential to get it wrong.

Those do not appear to be zeners, they look like plain old diodes to me. What types did you use?

Diodes "shorted to ground." By ground do you mean to the battery negative? By the schematic, ground is the positive.

[1WoodHippie]

I can't see what the orig Transistor type is. I can't make it out on the schematic and it's wore off the part itself. I need one with a leg pinout of BCE to make it drop in the circuit as it sits, but I can't find one. With the 3904 I have to bend/swap 2 of the legs to make that work.

I replaced the diodes with 1N4448's. I can't see what their orig part numbers are either. I assumed they were zeeners cause they are the clear orange-ish/red colored ones, not solid black like regular diodes.

By Shorted to ground I mean shorted to Battery Negative yes... sorry. As in... if I did a continuity check from the left side of R8 470K to battery negative it would conduct.

[Enzo]

OK. Not picking on you, just want to be accurate.

1N4448 should be fine. 1N4148 might be more common, but any small switching diode is good.

Many diodes are in glass packages, not just zeners. The plastic rectifiers are just more common in the 1A range.

Fair enough, the 2N3904 is EBC across the front. If in doubt, follow the trace from each hole and verify it connects to some component in the schematic as expected.

[1WoodHippie]

right... I traced each hole on the PCB in it traces to a BCE pinout. So I put in a 3904 and bent the C and B legs over to the holes they need to go in. Still dead..