engine noise thru speakers after blowing amp fuse

i recently blew the fuse for my amp, before that it sounded perfect, now-after replacing the fuse it whines, a little when the car isnt on, just the stereo, more so when it is on and i rev the engine. Someone said a grounded wire, but if that were so, wouldnt it have sounded like that before? Do i need to get my amp fixed, or possibly a new one?

i would bring it to a audio person that knows what they are doing and see what they think, if they can fix it, get a price and go from there. no sense of going out and buying a new amp if it's only going to cost 20 or 30 bucks to fix it.

try diconnecting the ground wire, sanding a little under it and putting it back on

i have done that, still has the whine, i think im going to have to pull it all out maybe re-do and replace the wires, cheaper then replacing the amp, especially if i dont have too. problem is, the way my room mate put everything in, i will be taking my entire car apart! yay!. im just a chick who knows very lil about this stuff, i guess ill be getting to know my car very very well! thanks for your help guys.