drag out the machine unplug the power,take the top off ,look towards rear of machine and you will see a cylinder with a pipe fitted to one end this pipe runs down to the door switch .pull pipe of cylinder and blow down pipe ,if door unlocks it could just have been a blockage in the pipe ,or you will have to replace the pressure cylinder ,if door doesn't unlock you will have to replace the pressure activated door swich .see how you go on, if you still cannot open door then its time to get the big screwdriver out and force the door open .
mech monster, October 2011