Mac II fan noise - an unauthorized solution

[Rich Morin]

As many of you may have noticed, the fan in the Mac II is *L*O*U*D*.  This
is either because the engineers assumed that the power supply would be used
at full power all the time, or perhaps because nobody realized someone would
be sitting next to the @#$%^ thing.

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:

  1)	Go to your local Radio Shack and buy a 3" (80mm) DC BRUSHLESS FAN,
	catalog number 273-243A, list price $14.95

	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 (!)).

  2)	Go home and find:

	a) A philips screwdriver
	b) a soldering iron and some solder and tape
	c) a pair of small diagonal cutting pliers
	d) a pair of long-nose pliers, preferably with quite skinny tips
	e) a small jar, to hold bunches of nuts, bolts, etc.

  2)	Power down the Mac II and related machinery, in some more or less
	graceful manner.

  3)	Pull off the cover of the Mac II and look inside.  On the left hand
	side is a shiny metal box (the power supply).  It is held in place
	by a single philips head screw, one or more external power cables,
	and an internal power cable.

  4)	Unplug the cables, remove the screw, and gently pull out the frobozz.
	(You may have to remove one or more circuit cards to do this - be
	gentle with them, and make notes about where they were and which
	cables they were using.)

  5)	Remove the two screws that hold on the cover, and gently pry off
	the cover, alternating sides until it comes off.

  6)	At one end, you will see the fan.  Just above it, you will see a
	set of wires leading out of the unit as the aforementioned internal
	power cable.  Clip the nylon tie that binds these wires to the fan.

  7)	There is a nylon clip holding the above wires.  Detach it from the
	binding post.

  8)	Unplug the fan, and clip the small nylon tie holding its wires.

  9)	Unbolt the fan and maneuver it out of the power supply.

 10)	Bolt the new fan back in place.  This is where the long-nose pliers
	come in, since there is no way to get fingers down into the space
	where the nuts go.  (The Panaflo fan used by the manufacturer has
	nuts built into it, but no such luck with the RS product...)

	The nuts from the old fan can be removed and reused with a little
	bit of effort (screw in a bolt and tap the nut loose by hitting the
	end of the bolt a few times), but you may just want to use some
	other nuts you have lying around.

	BTW, two bolts are plenty to hold the new fan in, if they are
	across the fan from each other.  (Don't kill yourself trying to
	use all four...)

 11)	Cut the plug off the old fan (~1.5" from the plug is fine), and
	attach it to the wires from the new fan, suitably shortened.  Wire
	red to red and black to blue, and tape everything up appropriately.

 12)	Remount the nylon clip, put the power supply cover back on, remount
	the power supply, plug everything back together, and try it out. 
	Put your hand down by the airholes in the power supply, to make sure
	the new fan works...


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...
-- 

  _ o  _ |_     _ _   _   _ o  _          Canta Forda Computer Laboratory
 |  | |  | |   | | | | | |  | | |      UNIX software consulting and training
 |  | |_ | |   | | | |_| |  | | |   {hoptoad,pacbell}!cfcl!rdm   +1 415 873 7841