hitachi dz-mv550 dvd camcorder

Hi, hope someone can help me with this , i have a hitachi dz-mv550e dvd camcorder that was working fine , now the dvd door will not open , im an ex tv/video engineer so i am capable of repairing it but i can not find any technical information about the fault, when you select disc eject nothing happens, the led does not flash to indicate that the door is opening, i would be gratefull for any information at all , many thanks , Pete