[comp.sys.apple] Cooling fans

NETOPRMS@NCSUVM.BITNET (Michael Steele) (04/20/88)

 I have a GS in a IIe box.  I just got my 3rd card and need a cooling fan.
  Are there any suggestions as to the best fan for the price...or are they
  all the same?

 Perhaps someone would like to get rid of an old IIe fan?  I'm just looking for
 the cheapest route.

 Thanks in advance.

-------------------------------------------------------------------------------
 Michael Steele NETOPRMS@NCSUVM.BITNET  All usual disclaimers apply
  co-sysop of the NCSU Apple Users Group BBS 919-783-9010 (PCP ncrtp)

cs2531bn@charon.unm.edu (Lazlo Nibble) (04/21/88)

> I have a GS in a IIe box.  I just got my 3rd card and need a cooling fan.
>  Are there any suggestions as to the best fan for the price...or are they
>  all the same?
>
> Perhaps someone would like to get rid of an old IIe fan?  I'm just looking
> for the cheapest route.
>
> Michael Steele NETOPRMS@NCSUVM.BITNET

I just hit my sixth card with a //e, and the cooling problem was finally
too much to take.  (So was the overload-the-power-supply problem, which is
why I don't have the seventh card in there anymore, but that's another post.) 
Even with the top off and a 5" fan constantly blowing over the motherboard, I
was getting erratic heat-related problems, like random characters popping up in
Applewriter.  Having the thing in a top-off configuration for three years
hasn't exactly kept the thing clean inside either.

So a few days ago I tore the whole computer apart, pulled the motherboard,
vacuumed out all the dust bunnies :-(, washed the case, resoldered the
connections on the speaker mod I had made, cleaned the contacts on all the
peripheral cards...and (here comes the relevant part):

        1) Pulled the out power supply, and
        2) Installed a little 3" Radio Shack fan inside, which I picked
           up from a friend for about $5.

This setup is working great.  With the power supply outside the case,
overheating is practically a nonissue; the fan inside takes care of anything
left over, and I don't have to reach around back to turn the thing on and off
anymore.

No doubt this would void your warranty if you tried it (I've had my //e for
over five years now so that wasn't a problem :-)...but it certainly beats
paying the $60 that all the "real fan" companies (Kensington, et.al.) seem to
want for their setups.  Apple power supplies seem to operate at temperatures
beyond those known to mortal man, so getting the power supply away from the
heat-sensitive stuff will probably solve your problem without even having to
play with a fan.

Something to consider, anyway.  It's certainly the cheapest route, if nothing
else.

Lazlo Nibble (cs2531bn@charon.unm.edu)

kamath@reed.UUCP (Sean Kamath) (04/24/88)

In article <2889@charon.unm.edu> cs2531bn@unmc.UUCP (Lazlo Nibble) writes:
>Even with the top off and a 5" fan constantly blowing over the motherboard, I
>was getting erratic heat-related problems, like random characters popping up in
>Applewriter.  Having the thing in a top-off configuration for three years
>hasn't exactly kept the thing clean inside either.
>
>Lazlo Nibble (cs2531bn@charon.unm.edu)

I know that with three cards and no fan, I was getting the same thing.  Then
with a fan and five cards, if I left in on overnight, weird chars.  Except
that it was always '?''s.  Aha!  I said to myself, what does this mean?

It means you have a bad 74LS245 chip on the motherboard.  Also, if may be on
the 80 column card.  THis chip is a tri-state bus buffer, and when it get's
warm, it sometimes doesn't go high-Z, I guess.  In anycase, make sure you
have a TI chip there, not some singapore sling.  I have succesfully left my
//e on for days, six cards and all, with only this change, with out a
problem (yeah, I have a fan. I ain't stupid".

SO: Check those 74LS245s,just to the left of the 80column card hole.  SHould
be next to an 74S109 (*not LS109.  If it's a LS109, it shouldn't be working
*at all*).

Sean Kamath

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jrt@MITRE-BEDFORD.ARPA (04/25/88)

	Greetings...Have to add my two cents worth to the cooling fan
discussions...

	I have had my IIe (with 6 slots full) running 7 by 24 for four (4)
years and have lost one power supply (the Apple original).  I replaced the
supply with an AE device of higher power rating and "tacked" a Radio Shack 12
volt D.C. fan across the Apple 12 volt line; then placed the fan up against
the back side of the case blowing into the slots where cables exit the case.
No problems since then (1 year of 7 X 24).  I had also lost three (3) I/O
chips on a home-brew speech synthesizer board which I attributed to heat build
up.  Like big mainframes the Apple seems to like one mode of operation, i.e.,
either leave it on all the time or use it for short durations, not a mix of
the two.  Since my machine is used for home-control it MUST be reliable,
available and recover from power outages, etc.  The basic box is pretty good!

	Jim