I bought my Alpine CDA-9886 several years ago and installed it in my custom Javelin at that time. It worked just fine at the time but had less than 1 hour on it. The car has sat for the last few years waiting for paint and other stuff. The battery has been disconnected several times over this time period. I removed the amp while the car was at the paint shop so it is possible they messed with the stereo while the car had no amps or speakers connected. Only the low level rca jacks have ever been connected. The front and rear rca's have no output but the sub rca's will drive the amp and speakers. The head unit has 3 switches on the bottom labeled ext. ap/ norm, but there is no details what these are for. I do have the owners manual that mentions that the non sub rca's can be used for inputs and outputs, but does not give any instructions on how to do this. I can not find an install manual for this unit.
Try pushing (with a pin) the reset button located behind the faceplate (lower left corner) as for the switches all must be set to NORM before powering up.