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Conference hydra::amiga_v1

Title:AMIGA NOTES
Notice:Join us in the *NEW* conference - HYDRA::AMIGA_V2
Moderator:HYDRA::MOORE
Created:Sat Apr 26 1986
Last Modified:Wed Feb 05 1992
Last Successful Update:Fri Jun 06 1997
Number of topics:5378
Total number of notes:38326

1375.0. "Turbo Fan" by DICKNS::MACDONALD (WA1OMM Listening 52.525) Mon Apr 25 1988 09:58

    I came across a solution to the "turbo fan" noise problem on the
    A2000. Apparently, the fan is pop-riveted to the power supply cage
    with zero isolation from vibration. A simple way to reduce the noise
    level by 50% is to drill out the pop rivets, widen the 4 mounting
    holes a bit, add grommets, and reattach the fan with nuts and bolts.
    
    From the mail I've read, this is a sure-fire way to reduce the noise
    to near A1000 levels.
    
    Has anyone here tried that yet?
    
    Paul
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1375.1BAGELS::BRANNONDave BrannonMon Apr 25 1988 19:358
    my fan isn't pop-riveted, just held in place by 4 screws.  I removed
    the grill to see if that made any difference - nope.  I like your
    idea though, maybe some felt padding between the fan and the metal
    case might help.  I suspect it is simply a noisy fan.  The XT in
    my office also has a noisy fan - is that the norm for the ibmpc
    world?  
    
    -dave
1375.2Instructions on Quieting the A2000 FanDICKNS::MACDONALDWA1OMM Listening 52.525Tue Apr 26 1988 09:3055
    
                      Amiga 2000 Stealth Fan Instructions


      Tired of listening to that Jet Engine Turbine fan on your Amiga 2000?
   Well, here's a solution  I came up with that cuts the fan noise down by
   at least half.  Over the course of the last 6 months, the noise of my
   Amiga 2000 fan slowly increased as the bearings for the fan started to
   make more and more noise.  Since my warranty was out, I decided to go
   ahead and pull the power supply and check out the fan.  To my surprise,
   when the fan was separated from the power supply and held by hand, it was
   almost whisper quiet, except for the noise the bad bearings generated.
   But when mounted in the power supply, the noise was terrible.  Drawing
   on my experience in the Submarine Navy, I realized that it was a simple
   problem of sound isolation.  The fan had been pop-riveted to the
   aluminum case for the power supply.  This direct metal to metal contact
   allowed the noise vibrations to transfer from the fan to the power
   supply, and from there to the rest of the Amiga case, amplifying the
   sound generated by the fan.
      The solution?  Well, I went to the local hardware store and bought
   four 1/8" x 1" round headed bolts with nuts and lock washers and four
   round rubber grommets with a 1/16" slot for the power supply casing and
   a 1/8" hole for the screws. These parts should only cost a couple dollars.
      Now, installation.  First turn the 2000 off and unplug the power
   cord from the rear.  Next, remove the 5 phillips head screws holding the
   cover on, and remove the cover.  There is one screw in the top middle
   of the back, and 2 screws on the bottom of the cover on each side.
   Next, remove the 2 screws on the back of the 2000 for the power supply,
   one is located at the top of the inside edge of the fan, the other is
   at the top, just above the power cord connection.  Now remove the 2
   screws that mount the power supply to the metal mounting bracket for
   the power supply and drives.  These screws are at the front of the
   the the supply next to the protective cage.  Now, unplug the cords 
   coming from the power supply to the motherboard and disk drives.
   You should be able to remove the power supply  now.  Ok, now to remove
   the fan, use a 1/8" or 5/32" drill bit and drill out the rivets
   connecting the fan to the power supply.  Next you need to drill out the
   fan mounting holes on the power eupply to accommodate the rubber grommets.
   The grommets I used required a 5/16" hole.  Now install the grommets,
   and mount the fan using the 4 bolts, lock washers, and screws.  I
   found it was easiest to install the bolt at the bottom right corner
   of the fan first.  (Looking from the rear of the power supply)
   Tighten the screws until snug, but don't overtighten.
   One last item, you should trim any of the rubber grommet sticking out
   on the side of the fan cover plate so that the power supply can fit
   snugly against the rear of the 2000.  That's it!  Now just re-install
   the power supply and the 2000's cover.

                                             Glen Nielsel
                                             CIS  75115,444
                                             BIX  gnielsel




1375.3Pop-RivetsDICKNS::MACDONALDWA1OMM Listening 52.525Wed Apr 27 1988 22:401
    Yep, mine uses screws too. Perhaps the earlier versions used pop-rivets!