Xref: utzoo unix-pc.general:240 comp.sys.att:2288
Path: utzoo!utgpu!water!watmath!clyde!mtune!hropus!homxb!ihnp4!ihlpa!kai
From: kai@ihlpa.ATT.COM (Irwin)
Newsgroups: unix-pc.general,comp.sys.att
Subject: Re: UNIX PC Fan problems, how I repaired it myself.
Summary: "7300"s had two fans originaly
Keywords: fan, unixpc, died, hot, repaired.
Message-ID: <7004@ihlpa.ATT.COM>
Date: 29 Jan 88 18:33:01 GMT
References: <234@icus.UUCP>
Organization: AT&T Bell Laboratories - Naperville, Illinois
Lines: 46
Posted: Fri Jan 29 13:33:01 1988

In article <234@icus.UUCP>, lenny@icus.UUCP (Lenny Tropiano) writes:
> [...]
> 
> the UNIX PC is a 12 volt DC 3" fan.  I went down to my neighborhood
> Radio Shack, and picked up:
> 
> 	Cat. No. 273-243   3" (80mm) DC Brushless fan    $14.95
> 
> I went home, got a phillips screwdriver and started attacking it!  To
> do the whole procedure took about 25 minutes, and the machine is up
> and running (still very cool after 3 hours).   I bought two fans,
> my next project is to remove the foam in the left side and replace that
> with another fan. (Hey, what's a little more hum?) :-)  I'll keep everyone
> posted.  I might just use that user controlled LED on the left side to
> turn it on and off at periods of time... Who knows?
> -- 
> ============================ US MAIL:   Lenny Tropiano, ICUS Computer Group
>                    ...{ihnp4, boulder, mtune, bc-cis, ptsfa, sbcs}! >icus!lenny 


The original 7300s had two fans mounted, thats the reason for the extra vent
(original 7300s had "7300" on the monitor bezel, not "UNIX PC"). 3" 12volt
roller bearing fans are pretty quiet compared to the non-roller bearing type
that comes in a UNIX PC, so two roller bearing fans have about the same amount
of "hum" as one non-roller type of the same CFM. 

I would just wire them up to be on all the time, so if one goes you still have
one left, just make sure you make a habit of putting the keyboard back in its
place in front of the floppy (the "other" fan tends to suck quite a bit of 
dust through the floppy drive, soaking up the oil on the guides for the head
assy. and you have to take the top off to relube these, not something you want 
to do a lot on a UNIX-PC, ease of service was not a high priority in the design)

just a little tidbit for UNIX PC owners, when the display seems to lose hor.
sync. or roll (a common problem on these machines) take off the top, clean and
bend down the copper grounding contact connected to the monitor base, about
95% of the time this is the only problem (bad grounding).




Ken A. Irwin
AT&T Bell Labs, Naperville
IHP 1A332
(312) 416-4485
...!ihlpa!kai