The thread I started a couple of weeks ago has expired off my news

We left our hero/sucker with a VAX 6600 that starts up for a few seconds,
then drops most of its power - only the fans keep running. Another
interesting symptom is that if I unplug the control cable to the XML-side
H7215, the rest of the regulators come up and are happy; of course, you
still can't run the computer. The error LEDs on the H7206B claim there is
an XMI-1 card in the XMI-2 backplane, which is not true; it's still on even
if I remove ALL the cards from the cage.

Someone asked if I'd looked at the output voltages from the H7215, and I
finally got time to hook up a scope. Indeed, the voltage comes up for but a
fraction of a second, then disappears. I checked two different outputs (+12
and -12) and get the same behavior. As I've said before, I've replaced the
H7206B and the control cable, and swapped the XML-side H7215 with the
BI-side unit (which powers up fine when I move the key to the appropriate

Any more thoughts? I appreciate your kind assistance -- Ian