The machine has been working normally until today when the drum wouldn't turn on any wash cycle, I turned it off at the mains, reset it etc as per the manual, it seemed to work OK, until it came to the spin cycle. When it spins the drum spins OK, but it is very, very noisy, a sort of clunking, rattling sound. I've had the back and top off, but can't see any thing obvious, any ideas?.