jabba wrote:

I bought a Index 645 that has a Baldwin DRO on it. This is
an old style with nixie tubes. The DRO has an independent
box for each the X and Y axis. The X axis worked fine, the
Y would not power up. I took it apart and fixed the power
supply to the nixie tubes and then it came on although one of
the nixies is burned out. Unfortunately there is some problem
in the logic chips I assume as the "zero" and "set" buttons do
not work correctly. Is anyone here experienced in fixing these
type of units or know where to get schematics?

What is happening and what is not happening on the readout. Does it
change when you move the slider? does it always read the same numbers
no matter what is done? The old readouts are compariatively easy to
fix. chips are cheap. Determine the general area of the problem and
then change some chips in that area. If the reset doesnt reset some of
the numbers, the drivers probably have a short or the input to the nixie
drivers. Get an ECG book with the chip pinouts and check the logic on
the chips... or just replace them one at a time.

John