6 Jun
2003
6 Jun
'03
10:30 a.m.
On Thu, 5 Jun 2003, Peter Turnbull wrote:
On Jun 5, 16:19, Tothwolf wrote:
I checked the voltages on the drive harnesses, and +5VDC and +12VDC seemed
to be within the normal variance. I'll see if I can't check +5VDC on some
of the boards too. I guess if that checks out ok, I'm to where I started,
thinking that there may be noise on +5VDC and/or +12VDC. Has anyone else
had similar problems with the BA123 power supply?
-Toth
Since we are on the subject of VAXen...
What would be the most likely problem with a BA123 MicroVAX II that
powers up, but sometimes totally locks up during the diagnostics? (I'm
not even sure it can boot, as some of the RD53s sound a little sick.)
I've pretty much eliminated the boards as the cause, and the only
things left are the backplane and power supply. It does have those
older power supply to backplane wiring harness cables, which I guess I
need to replace before I put many boards in the card cage.
Could be voltage drop between PSU and backplane, resulting in low
voltage on the cards. Part of the problem with the harness (which was
discussed here some months ago, in a different context) is that parts go
high-resistance. Check the voltage (especially the +5V) on one of the
cards.