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From: vanam@pttesac.UUCP (Marnix van Ammers)
Newsgroups: comp.sys.att
Subject: Re: Weird 3b1 fan behavior
Message-ID: <618@pttesac.UUCP>
Date: Sun, 15-Nov-87 20:03:59 EST
Article-I.D.: pttesac.618
Posted: Sun Nov 15 20:03:59 1987
Date-Received: Tue, 17-Nov-87 02:08:30 EST
References: <21740@ucbvax.BERKELEY.EDU> <30@icus.UUCP>
Reply-To: vanam@pttesac.UUCP (-Root Admin-)
Distribution: na
Organization: Pacific*Bell ESAC, San Francisco, Ca.
Lines: 31

In article <30@icus.UUCP> lenny@icus.UUCP (Lenny Tropiano) writes:
>In article <21740@ucbvax.BERKELEY.EDU>, maddox@renoir.Berkeley.EDU 
>(William Maddox) writes:
>| 
>| The 3b1 apparently uses a variable-speed fan.  On mine, the speed varies

>I have experienced the same symptoms.   The air from the "variable speed"
>fan on my UNIX PC 3B1 is warm... but I haven't had any problems with
>overheating.  (In fact it keeps my room warm :-) )  I know from experience
>that if the fan dies, your machine will follow suit rather quickly.  Those
>chips/power supply heats up real good!  I notice the faster speed only when
>and lots of noise all the time -- or one variable speed fan and noise only
>part of the time?  

You guys really make me wonder if the UNIX-PC has gone through some
revisions that we are not all aware of.  My 3B1 has one fan which hums
at a steady pitch.  The AT&T repairman who came out to change my hard
disk out told me that there was a heat sensing circuit in the power supply
which would shut the system off in case of overheating.  This only makes
sense.  For a few dollars it would protect the system from a burned out
motherboard in case the fan failed.

When you say that "you know from experience" do you mean experience
with an overheated UNIX-PC or do you mean experience with overheating
of computers in general?

Also, I suspect that either some of these UNIX-PC's have variable speed
fans, or they might have fan or power supply trouble.

Marnix
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