Hey everybody,hows it goin? I was recently building a temporary box for my subs. My mid tweet amp wasnt touched during the install. I hooked ub the subs to my sub amp everything looked good. turned system on to calibrate the sub amp and all I heard was ALTERNATOR WHINE

coming from my mids and tweets. I swapped the old rca's for a new one, still there.
So I tried both sets of rca's on the rear preouts, no more whine. So my question is are the front preouts fried at the deck, or could there be a grounding issue with the front preouts. I'm pretty sure that means they are fried, but just want to make sure.