Stereo reciever won't turn on?

I have a Pioneer stereo system and after taking it in a car in a car I hooked it up again and the reciever won't power up. I have tried different outlets. When I plug it in I can hear the subwoofer beep or pop or whatever but the screen won't turn on and music won't play. I oppened it up and the three fuses I can see are all still intact. What else can I try?