actually I'm going to bet your amp is fine

But I bet you don't ahve a remote turn on wire in your deck anymore

No big issue though, check to make sure you no longer have 12Volts at the remote turn wire....if you do, you have other issues and it may be the amp but if you don't then it's your deck. I personally would simply whip the deck out and put the remote wire from the AMP on to the Acc wire from the deck. This way the moment car switches on, so will the amp. Even if your deck is off the will still be running....no big issues though.