I handed down my cleaner and it has been returned -" it was having trouble getting going and now won't go!" was the diagnosis. Put a meter on it and found it was open circuit.
Stripped it tonight and found the motor brushes in a very sad state and a slightly burned commutator. I believe the cause to be a rather tight bearing at the pulley end of the motor (interestingly air cooled with a small pipe leading to the vacuum side of the motor). A clean up and refitting the brushed got it working - but it was running slow.
A replacement motor seems to be over £50 so I am wondering if I might be able to readily identify and fit a replacement bearing and set of brushes - or do I send it to the tip?