possibles,
A fuse box fault ,plug fault, fuse in plug blown,on/off switch 
door interlock 
check the plug socket outlet WORKS, use a kettle/hair dryer  (to prove its got power to it,) if yes now test the plug fuse if no go to the fuse box in garage or cupboard the next  thing needs to be tested with the POWER OFF using a meter or  buzzer .the on/off switch should buzz in only one position (closed ) if using a ohms meter it should   read  0 ohms in one position closed  and infinite in the other with the  switch open .the door catch is usually a replacement part 
 
(some times a shorted heater elements BLOWS the fuse )
                
 wirecutterman
                
 July 2010