Subject: Re: uVAX-II doesn't work without RQDX???
To: Gunther Schadow <>
From: Chuck Dickman <>
List: port-vax
Date: 04/15/2002 19:13:26
Chuck McManis wrote:
> At 10:39 PM 4/14/02 -0500, you wrote:
> >>You should be OK, but note that this system will catch on fire if you
> >>have the "old" wiring harness. The KDB50 is a power hog.
> >oops, now that's comforting :-) Are you serious? Won't a fuse
> >blowing out be a better alternative? How can I discern the old
> >from the new wiring harness?

Heed this warning. I had a chassis harness melt on me last year. I did
not pursue the DEC replacement, but made one from some parts I purchased
from DigiKey. The parts are AMP MTA .156. I used AMP 770522-1 contacts 
and 640250-9 hoods (2 hoods on each end.)
> Pull the chassis out of any wrapper (pedestal, etc) With the side cover
> plate over the front off (this would give top access to the drives/tape)
> look at the harness that connects the PSU to the back plane. If the RED and
> BLACK wires are all equal lengthed then you have the updated wiring
> harness. If the harness lays flat because the wires closer to the edge of
> the back plane are shorter than those at the end, then you have the
> "catches fire" wiring harness. The shorter power leads carry more current
> and the harness gets hot enough to ignite the insulation of the wires.

Another clue is that the hoods on BAD harnesses are yellow or red. In
researching this, I discovered that there were two fixes. One in which
connectors were changed, another in which the wire lengths were
I do not know which came first.

This makes sense to me, because in my case it was the contacts on the
wires that smoked. 
> --Chuck