This was my first "real camera", and it simply sucks that it's done. I got an awful lot of enjoyment from it. I bought it new in 2011, and it lasted for 116144 shutter actuations. It started protesting this spring, first with an invasion of hot pixels (which repeated mapping helped), and then with a nasty metallic slicing sound from the shutter, as if thin bits of metal were rubbing together improperly when the shutter actuated. The night before, the shutter failed on two frames while shooting a stack of 600 exposures. I had just started a new stack, and I was about 20 shots into it when it happened. I heard something snap inside the camera, a motor spun twice, and it shut down.
This is how it remains. I don't even have to turn it on. If I put the battery in with it turned off, it does the same thing. Motor spins twice, then it shuts down. Nothing on the display. No normal activity to the red LED. I can still access files on the camera's memory card by plugging it into USB, but I can't get anything on the camera's display. If I turn the camera off or back on, motor spins twice and then nothing.
I think perhaps a belt snapped, and so when the motor doesn't find tension the firmware is crashing. I'm guessing. I'll have to replace it as soon as I can, but I haven't been able to find a matching issue like this yet by searching, and I'm just wondering if anybody familiar with the internals has run into this issue before. I'll probably dissect it eventually, but having watched a teardown video I doubt I could repair it and get it reassembled without causing other problems.
Just for interest sake, here are the last two pictures I made with the K-r. They're each stacks of about 600 exposures taken manually through a microscope. The subject is a red admiral butterfly's scales.