your problem is you bought a SONY
Also check the speakers and the wiring. The harnes that conects the speakers to the wiring might be loose. The easyist way to check if its the speakers or the head unit is to test them. Use a battery and connect the + speaker to the battery and the corosponding - wire to the - side of the battery. If you hear a noise out of the speaker the is good otherwise the speaker or wiring is cooked. If your speakers are still good the buy a new head unit. (PIONEER all the way)
