Yesterday I received one of the frames for a slight repair and for enhancement. Time for a debrief...

It's large, quite heavy, but remarkably well preserved. And it's simple. There might be a loose joint somewhere or some oxide on a contact and I'll have to locate and repair it, while also figuring out how and why I made the circuit this way. In the hurry of the delivery, I had to cut some corners...

Remaking the PCB Could be a solution after all.