Car stereo shuts off

Question

My car stereo, ( Panasonic Cq-c511u ) shuts off @ exactly 9min 30sec every time i use it. There is still power to stereo when it shuts off. I have to either remove the faceplate for a couple minutes or eject a cd ad put it back in to be able to turn it back on. After getting it to turn back on it will again shutt off @ 9min 30sec. Any suggestions? Is there a security feature to this stereo I don't know about? I bought this car with it already in it, so I don't have the mannuel. Thanks!