Some machines test the motor rotation and if this is abnormal they throw a wobbler. Check out the carbon brushes in the motor. Theyre graphite blocks which transfer mains power to the copper segments of the motor - located at the other end of the motor from the drive pulley. Theyre probably worn down. They're quite cheap parts and easy to replace - the holders are plastic or bakelite and are generally held in with screws or plastic clips. Also, look at the copper segments they run on to check for burning or pitting. If the segments are burnt or damaged you need a replacement motor or a replacement armature (motor part) if you can source one. Occasionally may be a fault in the motor drive circuit board - in which case replacement of board only real option.
Check the pressure switch - a round item about 3 inches across with several wires connected, it sits under the top cover. Its an air operated switch which tells the machine water has reached the correct level. Disconnect the thin rubber pipe from the switch and blow down through it to clear any blockage. Switch itself may be faulty but its more likely the pipe is blocked.
Also check the filter - generally located behind a panel at the foot of the machine.Some are obvious like little square hatches and some are hidden behind the trim panel at the foot of the machine.
Check out this site for spares : www.4directelectricals.co.uk
Check out this site for info: www.2ndwave.co.uk/manual.html
dan
February 2008