My 2011 Chevy Aveo radio has stopped working. It turns on and lights up but I cannot change the channel nor is there any sound. I can hold the power/mute button and turn the radio off and back on but none of the other buttons are responsive. Every once in a while it will work, but for the past month it has mostly not been working. I checked the fuses and checked the connections at the speakers and all seem fine. Any ideas would be greatly appreciated.