Is the mirror stuck up? If so, gently slide a fingernail along its front edge and give a little yank down. Gentle. It is possible for the foam at the front of the mirror box to get so gummy that it can hold the mirror in place and basically stop everything else. If the mirror does come down, check its bottom/front edge for a thin stripe of black gummy particles.
This is your best case scenario. If this doesn't fix it, service is most likely the answer. For example, there is a bumper inside the camera that can also clog up the mirror motion. Heck even if it is gummed up foam, you should then buy a foam kit from interslice on ebay, $10 for a camera specific set of foam.
If it needs more, the guy to go to is Eric Hendrickson-
http://pentaxs.com/
For maybe $60-70, he'll get it singing again. Start saving now- the ME Super is a nice camera.