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From: jbm@celebr.uucp (John B. Milton)
Newsgroups: comp.sys.att,unix-pc.general
Subject: Re: Unix PC and WD2010B
Message-ID: <1990Aug21.211438.14843@celebr.uucp>
Date: 21 Aug 90 21:14:38 GMT
References: <32819@cup.portal.com> <25832@cs.yale.edu> <32963@cup.portal.com>
Organization: Celebrezze Committee
Lines: 38

In article <32963@cup.portal.com> thad@cup.portal.com (Thad P Floryan) writes:
>yarvin-norman@cs.yale.edu (Norman Yarvin) in <25832@cs.yale.edu> writes:
...
>If anyone IS having problems with their system(s) and hasn't checked the power
>supply voltages, do YOURSELF a favor and check/adjust them, especially if
>you've bought your system "used" and/or it's over a year old (yes, there still
>ARE brand-new, factory-sealed systems to be found (though they were manufacture
>d
>in late 1986).
>
>CAUTION: do NOT measure the voltages with your power supply free-standing, it
>MUST be connected to a load.  To set the +12 voltage it's best to use a "Y"
>connector attached to the HD so that the voltages are available on the unused
>connector for easier measurement; you don't want to, say, sneeze or slip, and
>short the probes against something and destroy your system(s).

Watch out here. Always clean off the power connectors FIRST. If you are having
an intermittent problem because of oxidation, you could OVER adjust your
power supply. The next time you bump your machine, the connector scrapes, the
oxidation falls off, the resistance drops and all of a sudden the system is
getting way too high a voltage. This can cause all sorts of damage all over
the motherboard.

Adjusting the power supply is like tuning up your car, fix everything else
before you try any adjustments.

HD2 production is still proceeding at EDA. I cashed the first 30 orders worth
of checks to pay EDA. Since they have to assemble boards by hand, I will get
finished boards from them in dribbles. As I test and verify, I will ship them
out. I still need to order more 26LS3[12] chips, and I need to find someone
with a ribbon cable press to assemble the motherboard to HD2 connectors.

Work is progressing slowly on the IBM to UNIXpc BussBridge

John
-- 
John Bly Milton IV, jbm@uncle.UUCP, n8emr!uncle!jbm@osu-cis.cis.ohio-state.edu
(614) h:252-8544, w:469-1990; N8KSN, AMPR: 44.70.0.52; Don't FLAME, inform!