Subject: Re: Vaxstation/MicroVAX info
To: David Heller <dmheller@frontiernet.NET>
From: Tim Shoppa <shoppa@alph01.triumf.ca>
List: port-vax
Date: 02/01/1998 21:50:16
> > No that was the BA23 with the unequal length power supply to backplane
> > connector.  The fix to keep that from happening was to replace that pretty
> > staggered length cable with one that has equal length leads.  The problem
> > was current hogging by the shorter leads and eventual meltdown of the
> > connectors from overload.
> 
>     Actually it's not so much the unequal length but lack of a tight
> connectin where the
>     connector plugs into the power supply.

Nope - you've got cause and effect mixed around here.  The uneven lengths
leads to some conductors carrying more current than the others.  These
conductors get warmer, and the connector for these warmer conductors
fails (the heat damages the springiness of the contact.)  When the
connector opens up, the rest of the conductors have even more current
to carry, and the process repeats until the wiring harness catches
on fire or the charred connector simply falls off or until the operator
smells the smoke and turns the box off.

Tim. (shoppa@triumf.ca)