Mine is in a 2004 Silverado and has the double height stereo with CD and tape player. I have found the cause of the problem at the inside end of the power push button. On the very end is an electrically conductive, black rubber ring (high tech material) which makes contact with four tiny contacts within the radio itself, thus turning the radio on. The high tech material of the ring apparently degrades and its conductive qualities fade - it develops a high resistance and will no longer function. I have proved it is the ring by using the nearly identical push button for "display" (below the power button) and its use in the "power" position causes the radio to turn on and off. PROBLEM: my Chevy dealer can't find the replacement part anywhere (their replacement push button does not have the bumper and ring portion), I can't find what the black rubber ring material is made of in order to replace it locally, and I haven't been able to find any reference to this problem anywhere (I can't be the only owner to have run into this issue). Anyone have a clue?