Hi Mike, you can try this it might work! I'm guessing you have error code E3? press & hold together the "load & EJE" buttons wait until the radio has checked through the CD's then release the buttons and see if it now works, if not disconnect the power both the normal supply and the memory (need security code!) for at least 30 seconds then refit fuses and try radio again, if this all fails a new radio will be required!!
nigel
August 2009