How do I fix a zoom G1 guitar pedal?

my brother was standing on my amp to hang something and it fell. he said everything was fine, but then I tried to use my pedal and the knob to the left (the one that changes between what part of the effect you edit) wasn't working right. it doesn't do anything when you turn it, and only works when you push down on it. I have a jam session tomorrow, so I need to know ASAP.

gmoon8 years ago
Could be a defective switch. Might be easy to replace--disassemble it and do a visual inspection. Zoom effects are usually cheaply made. I've got an older 505 which is worth what I paid for it new (not much), but it doesn't compare well to analog FX...