julian@bongo.UUCP (julian macassey) (05/13/89)
In response to the continued discussion on cooling the 3b1, here are my
AC fan installation notes.
Yes putting in an AC fan may raise your noise level, but it will shift
more air and not use 12V from the PSU when doing it.
I still have some AC fans available if anyone wants one, see an earlier
posting on unix-pc.general for exciting details or e-mail me.
yours
-----
Putting an AC Fan in the 3B1
You will need a three inch axial fan (115V) with at least
four inches of wire coming off it to do this installation:
Tools required:
o phillips screwdriver (med. sized. No 2)
o 1 small flat-blade screwdriver
o a pair of needlenose pliers
o wire strippers or a jack knife
Fig. 1 3B1 - Front View (keyboard and mouse omitted)
------
__________________________
|+----------------------+|\
||@@@@@@@@@@@@@@@@@@@@@@|| \_
||@@@@@@@@@@@@@@@@@@@@@@|| |
||@@@@@@@@@@@@@@@@@@@@@@|| A |
||@@@@@@@@@@@@@@@@@@@@@@|| |
||@@@@@@@@@@@@@@@@@@@@@@|| _|
||@@@@@@@@@@@@@@@@@@@@@@|| /
+---||@@@@@@@@@@@@@@@@@@@@@@||/---------+
/ == +----+--------------+----+ ==A=== /|
/ ======= | A | / ======= / |
/____A______|______________|/___________/B |
|###########|_____________________A_____| /
/ #C #C / /
/___________________B___________________//
|______________________________________|/
A is Monitor cover. B is base cover, leave on for fan replacement.
Procedure:
0) Do a full backup of your drive.
1) Make sure you have a cleared off table or desk with 4'x4' of space
to put the machine on.
2) Use /etc/shutdown to halt your machine. (Must be root)
3) Boot the diagnostic floppy, and park the hard disk's heads.
4) Turn the machine off, and unplug the keyboard and power cables.
5) Turn all your peripherals off.
6) Place your 3B1 on the edge of your cleared-off table, with the rear of
the machine projecting over the edge.
7) Remove the peripherals (printer, RS-232 etc)
8) Grab the phillips, and use it to remove the 2 vertical screws in the
back of the monitor case. They are normally hidden by the
peripheral plugs.
9) Hang one side over the edge and remove the two vertical screws there;
repeat for the other side.
10) Carefully lift the monitor up and towards the front of the machine - you
may need to use the larger flat-blade screwdriver to pop the front part
the case (next to the floppy drive) off. Be carefull here.
11) Set the monitor on its side. You may need to cut a cable tie to get
sufficient slack.
12) Locate the fan cable and disconnect the leads. Pop the end
connected to the PSU into the torroid in the PSU.
13) Lift out the DC fan and put to one side. Using a paintbrush,
compressed air etc, take this opportunity to flush the dust bunnies.
14) Using needlenose pliers remove the Power spade connectors from
the back of the IEC Power connector and switch assembly.
15) There should be at least a 4 ins pigtail of power lead on the fan.
Strip at least 1/2 in from each wire.
16) Each of the spade lugs has a little hole in the middle. Put a
stripped wire through each hole and bend over.
17) Push the connectors back on the spade lugs. This should leave no
uninsulated wire protruding. Adjust if neccessary.
18) The fan should have an arrow indicating direction of airflow. The
arrow should point to the back of the machine.
19) Seat the fan in the cavity and take care that the Hard Drive
power cables are not obstructing the fan blades. Adjust cable if
needed. Spin blades by hand to be sure.
20) Reassemble machine in reverse order to above and turn on machine.
21) Final check. Place your hand over the fan grill. There should be
air moving and it should be blowing outwards. There should be no
funny noises.
Job Finished
Thanks and apologies to pschmidt@bbn.com (Peter H. Schmidt) for providing
the inspiration and drawing for this document.
--
Julian Macassey, n6are julian@bongo ucla-an!denwa!bongo!julian
n6are@wb6ymh (Packet Radio) n6are.ampr.org [44.16.0.81] voice (213) 653-4495ins_anmy@jhunix.HCF.JHU.EDU (Norman Yarvin) (05/18/89)
In article <201@bongo.UUCP> julian@bongo.UUCP (julian macassey) writes: > In response to the continued discussion on cooling the 3b1, here are my >AC fan installation notes. Here are a couple of remarks on them. > You will need a three inch axial fan (115V) [..] The place for the fan is actually a bit larger than 3 in.; the existing fan is 3 1/8 in., and you can fit in a 3 1/4 in. fan. The existing fan is 1 1/4 in. deep, and it has a grate attached to it with double-sided foam tape which extends it to 1 1/2 in. You can fit in a 1 5/8 inch fan at most. > __________________________ > |+----------------------+|\ > ||@@@@@@@@@@@@@@@@@@@@@@|| \_ > ||@@@@@@@@@@@@@@@@@@@@@@|| | > ||@@@@@@@@@@@@@@@@@@@@@@|| A | > ||@@@@@@@@@@@@@@@@@@@@@@|| | > ||@@@@@@@@@@@@@@@@@@@@@@|| _| > ||@@@@@@@@@@@@@@@@@@@@@@|| / > +---||@@@@@@@@@@@@@@@@@@@@@@||/---------+ > / == +----+--------------+----+ ==A=== /| > / ======= | A | / ======= / | > /____A______|______________|/___________/B | > |###########|_____________________A_____| / > / #C #C / / > /___________________B___________________// > |______________________________________|/ > >A is Monitor cover. B is base cover, leave on for fan replacement. > >8) Grab the phillips, and use it to remove the 2 vertical screws in the > back of the monitor case. They are normally hidden by the > peripheral plugs. Note that these are the screws which connect A to B, not any screws that go into the actual box that contains the monitor. >10) Carefully lift the monitor up and towards the front of the machine - you > may need to use the larger flat-blade screwdriver to pop the front part > the case (next to the floppy drive) off. Be careful here. >11) Set the monitor on its side. You may need to cut a cable tie to get > sufficient slack. The whole top of the box (parts A and B together, normally removed as a unit) is designed to be lifted off the base of the machine and tilted backwards: then it rests (without having to disconnect any wires) on its back quite nicely. The front part of the case (right in the middle) contains a ratchet type mechanism for holding parts A and B together, which is hard to release: BBBBBBBBBBB B A B disk AAB ABB A B AAAAAAAAAAAAAA >14) Using needlenose pliers remove the Power spade connectors from > the back of the IEC Power connector and switch assembly. >15) There should be at least a 4 ins pigtail of power lead on the fan. > Strip at least 1/2 in from each wire. >16) Each of the spade lugs has a little hole in the middle. Put a > stripped wire through each hole and bend over. >17) Push the connectors back on the spade lugs. This should leave no > uninsulated wire protruding. Adjust if neccessary. Yeeeagh! This is a neat idea, but the connection formed is less than optimal, to put it in polite terms. I would advocate either (1) doing this the way I did, by buying appropriate spade lugs, and making the following device: (power jacks) | | { V V <--- PLUGS SOLDERED TO WIRES you { |\ |\ make { | \-------======== (fan) this { | | { | | <--- PLUGS SOLDERED TO WIRES V V | | | | (wires that went to power jacks) ---OR--- (2) putting the wires in the holes as in the original article, then soldering them in. This is easier, and if the soldering is done without leaving too much excess solder, it should still be possible to put the original plugs back on. In addition, this is an inherently permanent modification of the machine. >19) Seat the fan in the cavity and take care that the Hard Drive > power cables are not obstructing the fan blades. Adjust cable if > needed. Spin blades by hand to be sure. The existing fan will have a grill over it, attached by the aforementioned double-sided tape. If your new fan is small enough (mine wasn't), you can unstick the grill from the stock fan and stick it on your fan. Then you don't have to worry about cables getting in the way. For those who would attempt this without knowledge of how to solder: #1: Solder it anyway. Buy a soldering iron from Ripoff Shack, and experiment for a while. Your connections should be good enough so that a medium-light yank won't break them; if you can yank on it, you have a connection, otherwise you don't have a connection. Your connections should not be large globs of solder, nor should they be incomplete. (the 3 second guide to soldering) #2: Use method 1 from above. That way, you won't have to screw around with the soldering iron inside the machine, but can assemble the extra stuff before starting, and spend enough time to get it right. Those spade lugs can be very hard to solder; again, it's better to do it outside the machine. Good luck! May you not need it! P.S.: I would like to attend the Unix PC BOF in Baltimore, but mail to Lenny Tropiano bounced. Do you have to attend the conference to get into the BOF? (I won't be). My Unix PC is available for any non-destructive type (and even certain destructive types) of experimentation/testing. Norman Yarvin (seismo!umcp-cs | allegra!hopkins) !jhunix!ins_anmy or yarvin@cs.jhu.edu "Obviously crime pays, or there'd be no crime." -- G. Gordon Liddy