There is a sensor behind the right hand hinge that detects if the door is open. If that sensor fails then the oven will be convinced the dor is open all the time and the heating element will stay disconnected.
Getting to that sensor looks difficult as it is between the inner and outer walls of the oven so you may need to remove the oven completely from the cabinet and then dismantle the outer wall of the oven (this is a guess as I haven't tried it yet or found someone to supply the replacement sensor that I need)
The sensor itself appears to be a simple mechanical switch that is operated by the hinge pressing it as the door closes so it can also fail by the hinge breaking. It is then possible for the hinge to drop and not operate the switch as the door closes but if that hinge breaks then usually the door will either not fully open or fully close.
JB, August 2008
