The other day the aperture on my Minolta 50mm f1.7 prime stuck wide open. I suppose that after 25years service (I've had it from new), a problem might be anticipated but I was still horrified (like losing a good friend).
The cost of a professional repair is likely to be pretty high so I got a service manual from Pete Ganzel and got to work. Three hours later, after washing the iris blades in detergent I had the whole thing back together. I think lubricant from the Helicoid got on the blades! Why now?
Going to go out now and take some shots to see if it works.