Old rack gear keeps breaking

Sadly it turns out that most bits of rack equipment just don’t stand the test of time. I have been digging out some old bits of outboard to add them to the studio set up again only to find that one after the other they don’t work any more! It is probably battery power for the internal memories that has gone, which should be easy to fix with a bit of courage and a soldering iron, but its weird they all seemed to have failed at the same time.