GCB-95 doesn't wah anymore?

Started by moeburn, August 25, 2005, 10:35:27 AM

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moeburn

I woke up one morning to find that my crybaby doesnt wah anymore.  When i bypass it, it bypasses just fine, and when i turn it on, it sounds like it is stuck in the heel position.  The pedal is turning the potentiometer, and i tried replacing the battery.

AL

GEO FX. Technology of Wah Pedals.

That happened to a friend of mine. The DC jack had gone bad and the 9V wasn't getting through to the circuit. I just bypassed it since he didn't use an adapter.

AL

vanhansen

Look for any lifted solder pads anywhere that you have changed any components.  This happened to me.  I had to run a jumper from one point to the next to fix it because I lifted a pad.
Erik

Paul Marossy

Quote from: vanhansenLook for any lifted solder pads anywhere that you have changed any components.  This happened to me.  I had to run a jumper from one point to the next to fix it because I lifted a pad.

Sounds like a possibility. Those PCBs are really easy to screw up when modding them.

moeburn

Ok it wahs, but only a very little bit at the low end of the spectrum.  I opened it up and looked around, couldnt find anything obviously wrong.

SonicVI

Have you moved the pot's position relative to the gear at some point so that it's not turning into the upper range?

Paul Marossy

Quote from: SonicVIHave you moved the pot's position relative to the gear at some point so that it's not turning into the upper range?

That was my first thought, but I don't know how that would happen from one day to the next unless the nut on the pot came loose and the pot has shifted its position...

moeburn

The pot itself is fixed pretty tight in there.  I measured the resistance from the yellow wire to the black wire on the pot.  At toe, it was 50k, at heel, it was 95k.  Could someone confirm this?

Paul Marossy

Have you checked the 4.7uF cap? Usually, if that goes bad, your wah becomes a volume pedal - but maybe in this case it is causing your problem?

moeburn

I opened it up, adjusted the pot further to the treble end, and played it.  It seemed like it was working fine, then a few minutes later it just turned into  a lowpass filter.  It wasn't wahing or adjusting volume.

Edit: I watched the gears slipping when i slammed on the pedal really hard, they slipped really far and my wah became a bass wah.  I figured the crybaby moved the pot all 270 degrees, but i was wrong.  I may replace it with a 150k or 200k if they exist.

Paul Marossy

Maybe AL's suggestion is worth a second look...

no one ever

plastic gear-holder in place?
(chk chk chk)