There is a stainless steel belt around the drum, which is swept by a copper brush, which is then used by the control unit to determine how much moisture is left in the clothes. The higher the resistance, the dryer the clothes.
This brush may eventually wear away to a point where there is an open circuit.
to check unplug and remove the 2 screws at the top edge of the back of the drier. Then slide the top back and lift off. This copper brush I mentioned above will be plainly visible. If there is no good contact, the sensor programmes will not work.
the brush and arm can be bent easily to restore a good electrical contact.
Barry O'Neill
January 2009