when i first started messing with my stereo i accidentally hooked A wire up wrong, can't tell you which, thats why i say A wire. Anyways the stupid thing would turn off halfway sucking the cd in and then the cd would get stuck in it. Then it would turn on and off and sit there cycling power, although you couldnt tell, only when the car was off and quiet you could hear it clicking and buzzing. Took a dismantling and fucking around with pieces of a cd player in order to figure it out. Wired it up properly the last time and then it worked fine, it couldve been that the ground was loosely placed, i dunno.

but yeh, best bet is the thing is just fucked and its time to throw the cd player at the seller and get another one