Audio Systems: head unit, blown fuse, stock unit

Question
i recently switched out a stock head unit out of a 91 camry with a alpine 9856 and also put in two 12's and one amp. i have power to everything and it shows with the volt meter but the deck will not turn on, but when u plug the stock deck into the adapter it turns on. i am thinking the deck is a defect because i have tried absolutly everything and am extremely frustrated.

Answer
Hi Kyle, I think you having a problem seeing the wood for the trees.
Take the suspect unit out and hook it up to a independent 12v supply, (battery or that old CB PSU) and see if it works out of the car, if it still will not work, it's dead. make sure there is not a blown fuse on the leads or in the back of the set before putting it into orbit (or repairer. If it does work then you need to see where there migt be a difference between the stock unit and the Alpine.)
Good luck, Peter