John is wrong. There are two capacitors on the motor, mainly to surpess interference that the motor would generate. The checmical composition of capacitors can become leaky after a long time and they can then take too much current and blow up. They are only pence each to buy replacements and can be readily soldered in place. Whilst doing this it is a good idea to replace the motor brushes as a good bit of preventative maintenance.
Alan
February 2008