Hello, I'm new to the site but have been searching for a few days to see if anyone had posed this question. The issue was the mirror pre-release mechanism not working. I have since fixed the issue by disassembly and using Dick Werner's instructions, pried the lock up lever while re-assembling the body. I took the opportunity to lube the main gear and a few other spots he recommended with clock oil. The body is now extremely smooth and snappy. Since I acquired the body, lens and back, I've noticed the focus a bit off. I'm aware of the 3 pads under the mirror issue and I am going to be sending the camera in for a CLA, but I wanted to see if the issue could also be caused by the malfunction of the mirror pre-release lever. I will be taking some shots using a back/front focus test chart I use for autofocus lenses, and just need to develop them so I can use the images when the camera goes in for service. I figure it will help the tech narrow down any issues. Thanks for any information and a great resource (site).