Audio Systems: Car Stereo Dead? (DEH-P640), amp fuse, auto parts store

Question
Yeah, turned out that the fuses from one auto parts store sucked so I bought some more and they are working. I'm just using a 10 amp fuse. The unit not powers on. However, there is another problem... the speakers won't produce sound when the deck is hooked up. I put in the factory radio again and they worked, but when I plugged in the aftermarket deck no sound was produced. Is this just a short internally or something or do you think some stuff may have been fried?

Thanks

Answer
Jarrett,

   i dont know if i replied to this already but if i didnt here it is again haha ... if everything is kosher when you got the factory unit in then nothing clicks when the new unit is in i would say its been toasted , before you junk it see if you can get a shop to look at it that does small electronics repair just have them take a look to see if it is repairable ... or its time for the warranty if you have one

thanks