crate gx-80 low volume, no pot has effect on sound

[gary fish]

I have a Crate gx-80 amp. It amplifies a guitar at a medium level but the volume pot nor any other pot has any effect on the sound. there is no evidence of discoloration or bad solder joints. Does anyone know what might be going on with this amp. thanks.

gary

[movek1]

Have you given it the bang test.
turn the amp on, play your guitar, and lightly to medium, hit the amp on the side, or on top, (if there is a reverb tank turn it down or disconnect it), but hit the amp just enough to see if something is loose internally, if there is the guitar will either cut out or get louder