Functions do not work even after resetting.

When powered on, the display is there. Upon placing a CD into the drive it will play. I cannot change the volume. I cannot search, switch to FM/AM, I cannot do a thing with it except to power it down. I have removed the faceplate and pressed the reset button to no avail. I have seperated powere to it by disconnecting the wiring harness and reattaching and reseting. Nothing. Is there anything that I can do besides take it out and use it to break walnuts?