I plugged the sub woofer lead into the system whilst the power was on at the mains system which caused a small spark at the system socket. Since the sub woofer will power up but there is no life in the system. Serail number S/N 628000368
Try one of the internal fuses. Take the bottom off the subwoofer, this is quite a simple exercise, but involves quite a few screws, then you will be able to see three fuses, check these are all OK.
