Pentax ME Super shutter
 

I have a Pentax ME Super camera, bought around 1982. I hadn't used it for a while (using digital now, of course). I decided to use up some films before they got too old. The camera previously worked fine but now the shutter is erratic. I am finding that I have to wind it twice for each shot for the shutter to actuate; losing every 2nd. frame. I assume that the shutter may need some attention, but what? - and how? Hope you have an answer. Thank you in anticipation. redeyenewby. :o