So I'm looking at this 422 and the trace doesn't get visible until the
intensity control is around 3 o'clock. Blanking is adjusted, so
that's not the problem
This doesn't seem right, so I dug out the HV probe and took some
measurements.
The Accelerating potential is spot on at +4900.
But all of the negative voltages are just a tad off. The high voltage test point
at G1 on the schematic (labeled -1420 or -1400 depending on which side of the
line you're looking at) never gets below -1396. (At midrange it's -1390)
With the intensity at midrange, the cathode is -1360, not -1375 as spec'd on
the schematic.
Right now at the end of the intensity control, I get a range from -1375 to -1390,
so it looks like 10 or 15V can make a difference.
I hate working on HV supplies, but there's not a lot of parts in this one.
Anyone have any experience with this one? I'd appreciate some pointers.
Paul
--
Paul Amaranth, GCIH | Rochester MI, USA
Aurora Group, Inc. | Security, Systems & Software
paul@... | Unix & Windows
