Check to make sure that no wires have come loose and/or got accidentally grounded to the vehicle frame (such as through a break in the cable shroud). Make sure to check all wires: Speaker wires, remote turn on, power wires, RCA cables, etc. Also check the back of the player sled to make sure the "wires have pulled loose from my docking sled" problem hasn't bitten you.

Yes, it's possible the amp is bad, but remember that fuses are mainly there to protect against shorted wires.