Ok, now its all comming together. Yes some head units have the ability to turn off the internal amp so only the preout section is functioning. This however is not an option on the pioneer 7700mp. To the original poster of the question, here is an easy thing for you to try. Look at the amp and unplug the RCA's. Do the speakers quite working, if they do then the amp is hooked up to the speakers and working, so plug the RCA's back in and Enjoy. If you unplug them and nothing changes, then you got ripped off and back to the shop you go to confront them