I got this counter in april 2008 from a friend who knows my appreciation of nixie tube equipment. I was pleasantly surprised to see this was a nice large pice of gear. When I recognised it as a PM6630 counter, I felt a hope that this one might help me to fix my other PM6630, either by serving as an example as how its defective counter stage should work, or by donating some of its organs, or by replacing the other one.When I inspected it at home, I saw the case was a bit rusty in places. I suspect it has been stored in a damp place for some years.
So it seemed that the driver ICs were not working. It turned out that the +5 V supply voltage was missing. I checked the power supply and saw that +5 was missing. I checked the power transistor, which seemed to have its emittor dangling. And after some fiddling with the edge connector to the power supply board, the +5 came on, and so did the nixies.
Now the counter did count, occasionally. But the counting was visible, so it seems that the counter outputs are not stored. And a number of functions is working intermittently. It seems that I will have to clean a lot of connectors and switches.
To be continued...