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From: lenny@icus.UUCP (Lenny Tropiano)
Newsgroups: comp.sys.att
Subject: Re: Weird 3b1 fan behavior
Message-ID: <30@icus.UUCP>
Date: Fri, 13-Nov-87 13:57:55 EST
Article-I.D.: icus.30
Posted: Fri Nov 13 13:57:55 1987
Date-Received: Sun, 15-Nov-87 20:33:44 EST
References: <21740@ucbvax.BERKELEY.EDU>
Distribution: na
Organization: ICUS Computer Group, Islip, NY
Lines: 42
Summary: I have it too!

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
| rather erratically.  Not only are the speed changes annoying to the ear,
| but the fan seems to be running slowly most of the time, such that the air
| leaving the fan is warm enough that I am concerned that the machine may
| not be adequately cooled.  
| 
| I also have an older 7300, which has two fans that appear to always run
| at a higher speed.  It is quite a bit noisier, but runs cooler and is
| less annoying to listen to while trying to read or think.
| 
| Has anyone else observed this behavior?  Is it normal for the 3b1?
| Is there any way I can modify the machine to run the fan at full bore?
| Is there any reason why this would be a bad idea?
| 
| Bill Maddox
| ...!ucbvax!renoir!maddox
| maddox@renoir.berkeley.edu

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
it is real warm.  I guess it was a tradeoff for AT&T -- either two fans
and lots of noise all the time -- or one variable speed fan and noise only
part of the time?  

						-Lenny

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