I've had this deck in my car for about five years and all of the sudden the left channel went out. The two dash speakers are wired through the deck and both of them are still fine, but the other four speakers are run by two independent amps, one from front and one for back. The left side on both front and back conked out. Could the preouts for the left channel stopped working? does this sort of thing happen from time to time like it does for my dad's 40 year old stereo?