I've owned a lot of macs... from classics to LC's to performas, I've loved 'em all (well, almost all of them!) But it is with great love and admiration that I hold on to and continue to upgrade my G3 All-in-One. Sure, I would like a platinum powerbook - but I think the AIO is going to stay in the family for a looong time. It is by far the most reliable computer I have ever owned, and others feel the same way, based on many of the comments you'll read on the excellent G3 AIO site.

It was on that site I recently learned of adding a new quieter fan, so I thought I'd give it a try. About the only thing I don't like about the AIO is the vacuum-cleaner like fan noise that can get on your nerves after long hours of use. I have already successfully wrestled with adding hard drives, video cards, RAM, VRAM, firewire and USB to the AIO, so I felt I was ready for the challenge of that noisy fan.

So let's get down to business!

The first thing you should know is that this fan replacement will require the removal of the CRT (Cathode Ray Tube, commonly known as picutre tube or monitor) shielding, which is extremely dangerous. The voltages around the transformer and CRT are very high, and can kill. Modern computer monitors include electronics that reduce this danger when the computer is turned off, but it is still too dangerous to mess with if you don't know what you are doing. If you insist on tackling this, you should get instruction from a trained technician on how to discharge a CRT safely. Note - here is a link to a CRT disharge safety movie - this is NOT a replacement for proper training - no computer upgrade is worth dying for.

STEP 1: Remove front cover

Unplug your AIO! Always unplug electrical appliances when working on them. Unplug all the cables on the back too, they'll just get in the way later.

You'll have to get the front cover off your AIO. This is tougher than it looks! There are two small tabs - you can feel them on the underside of the cover - but if you try to pull it off by just yanking on the tabs, you're likely to break them. Help the process along by using a screwdriver or something similar to pry outward half-way up the cover;

STEP 2: Remove outer case

Once the cover is off, you'll have to remove four torx screws at these locations;

This gives me the chance to brag about one of my most prized possessions - my mega-long torx screwdriver! Many years ago, I complained to my mechanic brother-in-law that I could not find a torx screwdriver long enough to get at those screws at the top of mac classic cases. He used his connections to order me this ridiculously long torx from Snap-on! I like using it... kind of makes me feel like a computer-geek version of Dirty Harry!

There are two more torx screws to remove before you can lift the case off the AIO - they are at the top of the case near the front - they are covered by a couple of plastic tabs;

Once those torx are removed, you can simply grab the case and slide it up and off;

STEP 3: Remove CRT shield

Remember, this shield is here for a reason. Sure, it blocks electromagnetic interference, but once you remove it, you'll only be a misguided finger away from severe electric shock. Don't remove this shield without reviewing the warning at the beginning of this article.

Remove the six screws holding the CRT shield in place (not that four of them have finer threads for when you put them back);

You can then tip the shield up;

... just pull it off and set it aside.

It would be at this point that you should discharge the CRT for safety reasons. I think it would be inappropriate to attempt to describe instructions here - it would be more appropriate if you were trained how to do this in person by a trained technician.

STEP 4: Get the power supply out of the way

In an excellent bit of engineering, all that is required to move the power supply is to press one tab and lift. The power supply is held in place by two pegs that fit into holes - just lift the pegs out and the power supply swings aside. Get a pile of books ready to support the power supply - then press the tab, lift the power supply and set it aside on the bookpile (it will still be connected by many cables);

STEP 5: Free the fan

It would be great to undo a couple of screws and pull out the fan housing at this point, unfortunately, it won't slide all the way out unless the CRT is moved out of the way, and that's a big hassle. So I recommend cheating and dropping the fan out the bottom. So that means you will have to slide the main tray of the AIO out of the way so you can reach up with your hand. Complete instructions on how to remove the main tray of the AIO are on this page. After you have placed the main tray someplace safe, you can get back to the fan.

Method 1:

You need to trace and isolate the wires that run from the power supply board (see picture 1 below), down underneath the CRT (picture 2), to the fan housing (picture 3). This is a pair of black and red wires - it will be tricky to fish them out from underneath the CRT, but it's best that you do this to give you more wire to work with when cutting and splicing.

Unplug the connector from the power supply board and work the wire out until it is free.

Method 2:

Don't bother fishing out wires from underneath the CRT, and don't unplug the connector from the board (picture 1). Just cut the two wires as far from the board as reasonably possible to give you some wire to splice with. Now cut the wires right above the fan housing (picture 3) so that the old fan will be able to fall free when you unscrew it.

Now you can remove the two screws that hold the fan in place. These are designated by the green arrows in the picture above. When you remove them, the fan will fall out. Catch it!

STEP 6: Replace the fan

You're now going to grab your replacement fan and put that sucker in!

The fan that is inside the AIO is a 92 mm fan - so if you've got a replacement one that size, simply slide it up into the spot for the fan and run the wire through the hole in the housing. If the connector is not of the right type, just splice the wires and use the old connector.

But the fan I chose (thanks to info on the AIO page!) is the Silencer - a particularly quiet fan available from pc power and cooling. The problem is, the fan is only available in an 80 mm size, too small for the fan housing - and that means the holes to screw it in don't line up either.

Bill Simpson, a contributor to the AIO page, suggests using the hole for the wires (see red arrow in the picture above) for the second screw. I took a much stranger approach! I was a little worried about the fan being centered properly, so I drilled new mounting holes.

First, I lifted up the thermistor and removed the fan housing screw beneath it (see red arrow below), then I cut off the seemingly pointless spider-shaped cover of the housing.

This allowed me to get in close with a tape measure. First, I measured the distance between opposing hole centres on the fan, the I drilled holes to match. If you do this, lay a piece of paper towel underneath the drilling to catch any shavings.

I'm way too picky, so I hot-glued some dense foam to silencer fan to make up for the difference in size, and avoid any inefficiency in air movement.

Now just slip the fan in from underneath, run the wire up through the provided hole, screw the fan into place and splice the wires... here's how mine looked when in position;

Now just reverse all your take-apart steps to put your all-in-one back together! After starting up, I was extremely pleased to hear only the softest of fan noises - it's not "silent", but much, much quieter than the stock fan. What a relief! After a couple of years of leaf-blower noise, this is a real treat.

I took some temperature readings and it appears that the processor is running a little hotter - here are some before and after's;

I also swapped out a hard drive and added a new cable - it was too short, so I had to lay the cable partly over the heatsink, so I think that might be contributing to the higher heat. I'm going to get a longer cable that will sit out of the way. These babies run pretty hot, eh? But the temps don't seem too unusual - see this page. I've heard of people running G3's in the high 60's with no problems. Does anyone out there know how hot is too hot? Perhaps this new fan is inadequate?

Anyway, I hope you liked this nerdy upgrade story. Have fun with your new, quiet All-in-One!