OK, I made a very interesting discovery today. When I'm working on a project on my workbench, I normally have it plugged into a Variac. This ADM 3a is no exception. I bring up voltage slowly on any unknown old electronics, and then let it sit at our normal wall voltage - which currently reads 121V.
Today, for whatever reason, my Variac was turned down to 110V, and I didn't notice. I turned on the ADM 3a, and... it's fine. It beeped, it has a cursor, and scan looks perfect. I turned the Variac slowly up to 121V, and at around 118V the 3a goes nuts and loses horizontal scan, I just get the vertical line. So, some part is really marginal, and I need to figure out which one it is. What fun! -Seth
