Jim Dunlop Univibe repair

[veronica 1965]

I'm interested in repairing my Dunlop Univibe pedal by myself. The problem with it is, when I plug in, the volume of the guitar is vastly reduced and the tone sounds like someone set the guitar's tone knob to 0. I can't get a decent sound of it. Otherwise, it's perfectly fine; there isn't even any pot crackle! Does anyone know what might cause this or what parts I might look into replacing? Thanks!

[artifus]

you have a digital univibe? 

you may get a better response over in the main forum. in the meantime, here's some reading:

The Technology of the Univibe

[veronica 1965]

I tried to post this before in the build-your-own forum and the administrators moved me here. I figured I had to post things about commercial pedals here.

[starekase502]

A friend of mine had the same problem.  I noticed some of the nuts on the pots where loose.  When i opened the pedal i saw there is a ground point that is attached to what looks like a washer and is grounded to the case by the clamping force from the nut of one of the pots.  Open it up and you may find the same.  I really would have thought it would have made the pedal completely dead but who knows

[Fender3D]

Dunlop's Rotovibe has a 0.1uF capacitor from Input jack's signal switch to ground.
Maybe Univibe's schematic is similar... 
If your jack won't switch this cap off when inserting plug, it will act as a guitar tone control at 0