are you sure your battery is good?
Is the on-board trim-pot dialed to about the middle of its range?
do you have ground continuity on both in and out jacks and with the (-) battery connector?
go-zin-ta and go-zout-ta are not reversed?
plugged into the amp with no instrument, you ought to be able to at least get some noise from switching the switch around, shorting the input with your finger...
photos might help...
I ran across the same issue a while back, tunes out that I had a cord from CBG to Amp. Took me about 3 days before I tried a new cord and low and behold, I had sound.