What would cause my car radio to stop working?

Hello, i am having some troubles with my aftermarket pioneer avic ft700bt touchscreen radio for my 2005 scion xb. I took it to a local car audio shop and they hooked it up to another car and it worked just fine. But when i try to hook it up to mine i get no audio except for only the subwoofers, which are ran off RCA cables. I have checked all the wiring to each speaker numerous times and have found no two wires touching each other. I even tried hooking up another speaker that was brand new out of the box, and that didnt seem to solve the problem either, all fuses are still intact and i am still having trouble. Please Help?!