Awesome guide! I have a couple T4 and T5 cameras I'm working on, but I haven't found the culprit yet. A lot of them had leaky capacitors near the viewfinder, with one camera having a bunch of corroded traces due to the spilled electrolyte. Wiring jumper cables and installing a new cap seemed to solve the issue on this camera.

The other cameras have the same issue (lens move back in completely when the camera is powered off, and the lens sometimes gets "stuck" when the shutter is fired), but replacing the cap didn't fix the issue.

The shutter flex cables all measure out fine. Have you been able to find any other common issues with these cameras? I'd love to know and see if that fixes one or two of my Yashicas!