Chevrolet Repair: 1998 Chevrolet Cavalier Car Audio Problem, chevrolet cavalier, watt speakers

Question
I have a 1998 Chevrole Cavalier and I installed a CD player a few years ago and just recently it stopped working.  The CD player comes on and plays the CD but no sound comes out at all.  Sometimes I will hear a static sound and if I slap my CD player then it will come on but if I turn the volume up the sound will go out again. I checked all the wiring and everything and even hooked up another CD player to my car to see if it worked and it still had no sound.  Any ideas to what the problem could be?

Answer
First does radio work with it? if your still having same issues, check ground wires and all speaker wires. as well, check for an in line fuse, if none, put one in.. cheap and easy. next double check all wires, grounds, power etc. make sure you installed it correctly and don't have any wires touching. without looking at it.. its hard to say but check it systematically, one thing at a time and eliminate and move on.
check speakers as well. your player may not be able to push the speakers.. ie  low watt stereo high watt speakers.