Had probs with my xplod, wired up but no sound - came across this useful article which did the trick, still gotto figure how to mount in my car tho!
Notes: One common thing people seem to have problems with is the amplifier shutting down due to an "Offset" error (indicated by the "Offset" status LED glowing amber, see Figure 1b above). Almost 99% of the time, this is because the case of the amplifier is grounding through the mounting screws to the car chassis, or some other piece of metal below it. This creates a ground loop and the amplifier's protection circuitry seems to be sensitive to this scenario. I *highly* recommend mounting this amplifier on a board, then attaching the board to the car floor / mounting point separately. Make sure you don't drill into a gas tank or anything. Using rubber grommets in the amplifier mounting holes for the screws can help also, but is not always reliable. If this is not the problem (you already have the amplifier on a board/etc), then check your power and ground connections, make sure all connections are tight, and that your speaker terminals / leads are not grounding to the chassis either. Also always ground all amplifiers to the same point on the car chassis.
Hope it helps
Riz
Good solution, not common, that's for sure. The only times I see it is when the amp isn't mounted at all or if the screws that are mounting it to the board go through the board and touch the bare metal.