The fan in my Kensington System Saver IIgs was giving unmistakable sounds of
failure mode- a wobbling rumble- so I decided to  replace it.

I consulted the FAQ and found the nice description  here

http://home.swbell.net/rubywand/Csa2POWER.html#017

Having finished the project I have a few comments for others who may be in
my shoes.

(1)  I chose the ball-bearing version of the fan that is supplied with the
System Saver.  It is a Comaire-Rotron Sprite SU2B1 Digi-Key part CR103-ND.

It is almost but not quite a drop-in replacement.  The mounting holes are
not threaded, so a 10-24 tap is also required.  Smaller diameter bolts, nuts
and washers would also work.  Two crimp-on 1/4" spade-type female connectors
are also needed, or butt connectors to splice on the old ones.  I imagine
the sleeve-bearing Comaire-Rotron Sprite units also require threading.

(2)  The old foam weather stripping had deteriorated so I removed it.  A
flat-blade screw driver worked.  I also discovered that there is a thin
plastic backing that you can tease up and peel away.  It is fragile but it
does help a bit.

(3)  The recommended 3/8"w x 3/16"t weather stripping may be a little thin.
3/8" x 1/4" would probably seal better.

(4)  The new fan definitely delivers much better air flow, but is quite
loud.  I suspect that the sleeve bearing units were not chosen to save money
but because they are quieter.  When I began I did not have a sense of how
noisy 40dB is, but it seems quite loud (I am sure worsened by turbulence
within the SSIIgs case and the louvers above).  It is of course nominally
about 5 times the loudness of the 26dB sleeve bearing fan, but the increased
air flow must accentuate that difference.  In retrospect, I would probably
choose the quieter fan if I were doing it again.


Frank