I might also try disabling the 0db option and try turning the volume control to see what happens. There have been times with my unit when it will start up and have no volume. This seems to occur if I stop the bootup process in the middle. Such as when the car doesn't start quite right and I turn the key off and back on again before the unit had a chance to finish booting. I know this is an AC power problem and probably isnt related. Good Luck