i just removed my 4 channel amp because it overheated and it was connected to my 4 component speakers. I rehooked the 4 speakers up to the internal amp in my headunit and it sounded fine. So i decided to go for a drive and i turn it up to about 60% power and the speakers all shut off. I have a separate amp for my sub and that was still playing music. The headunit was still on. its just there was no sound at all coming out of the speakers. I checked the fuse in the back of the headunit as well as the car fuses and they are all fine. Any ideas on what could be wrong?