Zanussi FL1084 (Circa 1996 Model.) Blows mains fuse intermittently?

At different points in the wash or rinse cycle I have seen the power lamp flicker and if the machine is left switched on, the mains plug fuse blows. The drum appears to be trying to start to turn again after stopping for the reversal.

Ideas:-

Motor: checked for damage and brushes are ok. (DC Motor therefore no capacitor.)

Heater element: Very furred up but works normally and I would have expected the Mains RCD to trip if this was bad not the plug fuse. Also this isn't used on rinse cycle.

Pump Motor : The problem has occurred in mid Wash cycle so pump not operating at the time.

Inlet Valves: disabled the Hot inlet and eliminated it, cold valve could be suspect but don't they usually fail completely rather than intermittently?

Foreign object jamming Drum intermittently? How to find out?

He......lp

Romeo Delta