One day I started my truck and I no longer had sound from my JVC stereo. Everything lights up and channels and volume changes, but no sound from the factory speakers. I have been assured that no wires have come loose. Sorry to ask a relatively vague and most likely simple question, but could this be something as simple as a blown fuse as opposed to the system being completely shot. I just want to check everything out before I just go an get a new stereo if there's an easy fix.