I have had no problems myself, but as a long time musician who has hooked up a lot of sound equipment, it sounds like one of 2 problems. Either the power amp is damaged, or there is a problem with the connections. It would be highly unlikely to have a failure of so many speakers at the same time. I think the power amp is in the trunk behind the driver side panel/door. Check to see if any of the wiring harnesses are obviously disconnected. Beyond that, this is too expensive of a stereo to tinker with (unless that is a specialty of yours) so I would take it to the dealer.