Mac II fan noise - an unauthorized solution

[Joshua Golub]

In article <309 at cfcl.UUCP> rdm at cfcl.UUCP (Rich Morin) writes:
>
>As many of you may have noticed, the fan in the Mac II is *L*O*U*D*.  This
>
>In any case, if you have the usual small number of cards in use, and feel
>brave, a solution is at hand.  Here is a completely unauthorized hack which
>will almost certainly break your warranty, but which may also save your sanity:
>
>	This fan draws half the current of the old one, and no doubt pushes a
>	bit less air.  It is also considerably quieter (one can actually
>	hear the disk over it (!)).
>
    ( Hacking instructions deleted )
>
>Please note - do this at your own risk, flames to /dev/null, and don't post
>responses to comp.sys.mac, 'cause I don't read it  (I *do* read comp.unix.aux,
>albeit erratically).  Just thought this info might come in handy, is all...

This is the third or fourth posting of fan replacement instructions, and no
one yet has mentioned the 'extra protection' Apple provides.  According
to my Mac II manual (the one labeled Macintosh II) the fan will work harder
if the machine gets hot.  (Check the 'troubleshooting' section under 'noisy
fan')  I'm assuming that there's a sensor which gives the fan a little more
power when it gets hot.  Now, I've never heard my fan speed up, it stays at
a nice, consistent level of loud, but it's nice to know that, if the back gets
clogged with dust (or whatever), I'll have some sort of warning.
   Have any of the fan-hackers tested this fan power increase with their
new fans?  Can I add some sort of LED to warn me when the Mac II gets hot,
and then go ahead and install a quiet fan?  Or should I try to keep dust
(or whatever) out of the case and pray. . .
   Yes, the fan is loud, and yes, it sits about a foot and a half away from
my head (next to, not under, the monitor) but I can still (barely) hear the
hard drive over it. . . what a pain.
   I should also point out that the power supply is a repair package, and if
something nasty does happen to the power supply, and you've torn out the
fan, that Apple won't fix it.  They will, of course, supply you with an
entirely new supply at about three times the cost of a return/repair.
 
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