I got a knock at my door one evening from one of my neighbours asking if I “knew anything about electrics”; it seems that is my reputation in the stair. I hadn’t noticed as it was May and the nights were short, but the stair lighting had stopped working. I had a peek and it turns out we have a Sangamo time clock that’s apparently very common in the Central Belt. It’s usefully described in one of BigClive’s many videos.
I expected that it was just the battery that had failed, so I replaced it. When this didn’t make any difference I had a closer look. They’re quite fascinating devices, basically a big electro-mechanical watch, and frighteningly accurate given their entirely autonomous nature.
You can just about see it, inline with the right of my thumb, where one of the brass sheet metal parts had decided that ~25 years of service was quite enough for it and folded back past the intended 90 degrees. There was a score mark on the brass, presumably designed to induce a fold at the correct place, but inevitably also leading to a stress riser. I took it to bits.
I straightened up the tab and put a big fillet of (soft, electrical) solder across it to hold it in place.
Not without significant difficulty, the thing was reassembled. If you look closely you can see the repaired part in-situ here.
Tin/Lead based solder isn’t really the ideal method for the repair here, it was what I had to hand and was only really intended to a) see if that was the problem and b) fix it temporarily until some future date. As we all know temporary fixes have an alarming facility for becoming permanent. At the time of writing it’s been nearly 4 years, so I think if it was going to fail again it would have done so already.