As I say to most - REPLACE IT - Stereo's are too tricky to go and try and figure out what is wrong. There are a million components to them and they are picky bits of technology. If they break, its usually due to wear and tear, and apart from taking it to a stereo specialist, the best way to fix it, is to replace it
**Working PART-TIME for Carjunky for a while, Please bare with me =)**