I have the same problem with my Spider 120. It won't accept any signal. In addition, when I plug in the headphones, I hear a strange rapid electronic "click, click, click, click" in one side of the headphones (it doesn't sound like a click track). Nothing plays through the USB port via my iPhone. Every thing lights up in the LCD panel, I can change settings, etc. When I switch to the tuner, it lights up, but again, it registers no signal. I've also recently upgraded to the latest firmware version. My amp is still under warranty for a couple more months. There are no service centers within 200 miles of my location (I checked on the Line 6 service site). Do you have any suggestions for me or do I have to return it to the factory for warranty work? If it's the latter, please provide a link with instructions on how to do this. I love the amp and just want it back in working condition. Thanks.