If you press the machines power on/off switch a few times fairly rapidly, does the power turn on/off then? I think that it wont so if it doesnt, the first thing to suspect is the obvious....the power switch itself has gone faulty in a short circuit condition.
Before replacing, you can confirm if the switch is faulty by using an electrical multimeter to test it - perhaps someone could let you borrow theirs. I cant believe that replacing this switch would be a big job but others with experience in doing it, may disagree.
Personally Id get this problem fixed before using the appliance any more. It wont fix by itself and the problem needs to be addressed sooner or later so why not sooner. The risk to your personal safety cannot be assessed from anyone behind a computer, so why take chances.