Answering my own question here.
Removed back of machine and took off all hoses. Wires to the motor etc run at the back. A number are held by a small cable strap onto the back of the drum. Apart from insulation tape - theres no gromit protecting cables. On investigating - clearly see a cable had started to wear through and so shorting to the casing. Put a sleeve on cables - taped them up and tied them back. Problem fixed.
Paul Roebuck
March 2007