at the start of a wash cycle - one brief, but very powerful,
anticlockwise spin of the drum, then timer cycles through to
stop very quickly with no further attempt at filling or washing.
motor speed sensing magnet on the rear of the motor had come
unscrewed, taking its cover/cage, and pickup coil off the motor.
(these items were lying on the floor underneath it!):
the motor controller didn't know what speed the motor was running
at, which explains the one full power burst of motor activity.
straightened out the prongs on the cage, and cover, to fit snugly
inside the pickup coil. (refit in the indentations in the plastic)
Refitted the magnet (tightly) in the end of the motor shaft,
and refitted (push fit) the whole pickup assembly.
So far, so good..