I just had the same problem. It scared me because I have a show coming up soon. I use the G10 wireless transmitter so I was thinking that it went bad on me. I tried a regular guitar cable and still had no sound (the drum beat button still worked but that wasn't helping me). I began to follow someone else's instructions to reset the amp to factory settings (which I didn't want to do because I have custom settings that I love). Holding down the Home button, I saw that my wireless was on channel six. I plugged the G10 into the amp and watched it cycle through different channels until it seemed to be happy with channel 1. Then I plugged it into my guitar and BAM! I was back in business! I hope this helps you guys and I hope it never happens while any of us are onstage.