Yes, as he said chances are a fuse has blown.
There is likely to be more than one possible fuse that might have blown. For instance, it could have been the inline fuse on the player's constant power wire (yellow), or it could have been one of the fuses on the car's main fuse panel.
The important thing is that you should find out what caused the fuse to blow in the first place, and correct that problem. The fuse blew for a reason, and if you don't fix the problem, you could fry your amp or your empeg.