Photofsckery part 2/n. New lens, acquired for about US$7. Not ID'd by camera, "00" aperture, error 01 (lens comms error) upon shooting. Found corrosion on traces, pads and vias, plus one TVS diode pin eaten away, plus bad fingers on the focal distance encoder. Patched all that minus the bad TVS, due to not having a suitable part on hand...
Did the unimaginable and broke a FFC connector locking tab for the first time in years, but all else went back together okay. AF seems to work but hunts constantly, will try with another body in case the AF sensor is bad, or the mirror too dirty on the 40D. Don't think it's got anything to do with the connector mishap, though I'll also fix that when I go add the TVS. Just a 4 pin part, wide pitch..
Anyway, TIL: camera lenses may also need capacitor replacement π


