Subject: csa2 chronicles: hacker's corner
From: [email-masked]
Date: 23 Nov 1996 20:40:50 GMT
Newsgroups: comp.sys.apple2

Hacker's Corner

Replacing the System Saver IIGS Fan

Does your Kensington System Saver IIGS sound like a broken record?  It may
be that the fan inside the unit is showing wear.  The good news is that
replacing the fan is an easy and rewarding task.

I knew my fan was starting to die when it sounded like it was wheezing
during spin-up.  The fan, a Sprite model SU2C7, uses sleave bearings,
whose lifespan is determined by the lubricating oil supply in the
bearings.  When enough of the oil evaporates, metal will grind against
metal resulting in heat and resistance that cause the fan to quickly
lock-up.  Better quality fans use ball-bearings, but Kensington
apparently used the cheapest component available.  Even among the models
with sleave bearings, the SU2C7 is the least capable.  It can only move
15 cubic feet of air a minute (half what a typical PC fan moves) and has
a 55,000 hour rating.

In looking for a replacement for my dying fan, I chose to use a better
model.  The Sprite model SU2B1 has the same dimensions as the SU2C7 used
in the System Saver and is readily available from Digi-Key corporation.
It uses ball bearings for long life (the fan is rated for 73,000 hours)
and can move 28 cubic feet of air a minute.  The higher quality is
readily apparent: the replacement is currently noticeably quieter than
the original even though it is moving more air per minute.

Make sure the System Saver is unplugged before opening the case.

Opening the System Saver case involves removing eight screws.  You must
remove the foam weatherstriping along the periphery of the case to expose
the screws.  Once the weatherstripping is removed, you should be able to
see the screw access holes.  They are arranged as shown in the following
diagram (bottom view of the System Saver):

                                FRONT
 ______________________________________________________________
|   ________________________________________________________   |
|  |                                                        |  |
|  |                          *                             |  |
|  |     _____________                                      |  |
| *|    |             |         Screw holes revealed ------>|* |
|  |    |             |         after removing foam         |  |
|  |    |     Fan     |                                     |  |
|  |    |             |                                     |  |
|  |    |             |                                     |  |
|  |    |             |                                     |  |
|  |    |_____________|                                     |  |
| *|                                                        |* |
|  |                                                        |  |
|  |                                                        |  |
|  |                                                        |  |
|  |                                                        |  |
|  |                                                        |  |
|  |                                                        |  |
| *|                                                        |* |
|  |                                                        |  |
|  |                          *                             |  |
|  |________________________________________________________|  |
|______________________________________________________________|

                                BACK

Once inside, the fan can be removed by unplugging the power cord that
connects it to the circuit board.  A grounding wire that is attached by
a screw must also be removed.  The fan itself is held to the case by
two screws.  Once you remove the SU2C7, you can replace it with the
SU2B1.  Now mount everything back together again with the screws. Apply
new foam weatherstripping to the periphery of the bottom of the system
saver.

The refurbished System Saver is now better than a factory new model!
Notice the difference in sound: a quiet hum rather than a load rumble.
If you have a lot of cards, you will notice that the inside of the IIGS
is a lot cooler too.  An upgraded System Saver is a great way to
counteract accelerator instability caused by heat.

Sources and parts needed:

1) Part: Sprite model SU2B1 (Digi-Key Part No. CR103-ND)
   Source:  Digi-Key Corp. (1-800-344-4536/www.digikey.com)

2) Part: Foam weatherstripping tape (3/8th inch width, 3/16th inch thick)
   Source:  Home Depot (or a comparable hardware store)