27 Feb
2000
27 Feb
'00
6:45 a.m.
Dr. Mark wrote......
My experience when I worked at an HP2100 site was that
about 50%
of the problems had something to do with the backplane. You
probably don't want to hear this :-). Check for dirt or dust
in the connectors. One of the things the service people did when
they got strange problems was vacuum out the entire backplane.
For some reason HP2100s suffered more from bad backplane connections
and dirt than other machines I've used.
I use a particularly fantastic contact cleaner designed for gold. I can't
say enough good about it. Now I use it on all cards and connectors I get
during the cleaning process. My backplane has been very babied :)
If a quick clean of the backplane doesn't work,
its probably
a good idea to check to power supply (its easier) before going
back to the backplane for a more careful examination.
Ok, I dug through some info on the power supply. It appears that the IPU
(Internal Power On) and PWU (power up) signals should go from 0 to 4vdc +/-
1v within 1/2 second of line voltage crossing 102vac. On my good machine
they do, on this one they don't. It appears now that there is a problem with
the A3 control board which monitors power and is the originator of IPU and
PWU. If the revs of the boards are the same I'll try switching them. In any
case, at least it seems to be isolated to one card.
Thanks for all who responded, I'll let the list know what I find.
Jay West
PS - who was it that had a 2100 for years and hasn't touched it? Aw c'mon -
give it a good home - I do know one ya know <GRIN>