I'm having problem with said amp, I can't switch channels or turn effects on/off, and sometimes acts really strange while trying to switch effect. It's the same thing if I'm using footswitch or pressing buttons on amp.

The only thing I did different than before with amp is connecting it as PC speakers in AUX in, but I just tested it and switched off shortly.

I tried searching on internet and nothing came up, so do you have any idea?