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Adding a thermometer to the G4 Cube.

April 23, 2008 Leave a comment

After replacing the original 20GB drive with a nice new one, I got a little concerned about the temperature. I’ve installed a 1200 rpm, practically silent (19dB) fan in the base and wonder if it’s enough to offset the heat generated by the 7200rpm Hard Disk. 

So, for the the third and final installment on modestly modding my Power Mac G4 Cube, I’ll show how and where I added a thermometer to measure the drive temperature. This should take about five minutes.

Get yourself a nice digital thermometer with a surface contact probe, like this:

Contact Sensor Digital Thermometer

 

The temperature probe should be small enough to fit through one of the holes in the bottom of the Cube’s casing:

Thermometer Wire

Opening the case:

      First make sure you have the thermometer, some aluminium tape and enough room to work on,  i.e. a flat, clear surface within easy reaching distance.

  • Unplug the Cube and invert it. Take care not to scratch the machine’s plastic case. I inverted mine onto a pillow.
  • Push the rectangular, inset bar located on the upturned base in firmly, until you hear it click. Now release it. The handle should pop out.
  • Use the handle to lift the chassis out of the upturned case. If this is the first time it has been removed, it might take a little teasing to get things moving.
  • Lift the chassis out vertically, taking care not to scratch the insides of the case with the metal corners of the chassis. The chassis has no sharp corners so this is not a serious issue. Still, it would be a shame to scratch it.
  • Now place the chassis down on a flat, clear surface. Take care not to damage the sensor on the top of the unit (probably facing downwards since it’s the side opposite the handle).
  • Push the handle in all the way and let go. It should stay in place.
Connecting the Thermometer
  • locate the side of the Cube where both the RAM and the HDD are visible.
  • Push the probe up through a hole in the bottom of the case. Somewhere near the BIOS battery is a good area.
  • Pull in as much wire as required and bind the wire tightly with a wire tie to one of the internal posts. There is a space above the Airport sensor on the the side, perfect for this purpose.
  • Tape the sensor to the side of the drive firmly with aluminium tape.
Fan on side of Mac Cube
Now reassemble the computer.
I found that when actively using the Cube, the drive would reach about 40 degrees when active. A lot cooler than the 55 degrees it used to reach before installing the fan.

 

Categories: Mac, mods, Technology Tags: , , ,

Installing a Large 128Gb+ Hard Disk in the Mac G4 Cube

April 21, 2008 1 comment

I’ve been running my G4 cube with a large hard drive since just after I bought it in May, 2005. I thought it was time to show you the quickest way to replace the drive in 10 minutes, without any major disassembly.

The Cube is a product of its day and I’ve had mixed results with high capacity drives in my Cube, including drives that “should work”.

Firstly, bear in mind that if your drive is larger than 128Go (A Go “Giga Octet” is the new way of saying GB when you mean 1024x1024x1024 bytes rather than 1,000,000,000 bytes that the drive manufacturers use to inflate their drive sizes 128Go is about 132GB) , you’ll need to purchase the

Intech ATA Hi Capacity Driver for Mac OS X

Or else your computer will only recognise the first 128Go, regardless of the drive size. I’ll discuss this in a later post.

Update: You can use an Open Firmware hack to achieve the same thing. Read here.

You’ll need a set of Torx drivers for the star shaped “security” screws. Sizes T8, T10 and T12 should do the trick. You will also need a medium sized pair of pliers for some minor and painless case modifications.

Opening the case:

       First make sure you have the fan, the torx drivers and enough room to work on,  i.e. a flat, clear surface within easy reaching distance.

  • Unplug the Cube and invert it. Take care not to scratch the machine’s plastic case. I inverted mine onto a pillow.
  • Push the rectangular, inset bar located on the upturned base in firmly, until you hear it click. Now release it. The handle should pop out.
  • Use the handle to lift the chassis out of the upturned case. If this is the first time it has been removed, it might take a little teasing to get things moving.
  • Lift the chassis out vertically, taking care not to scratch the insides of the case with the metal corners of the chassis. The chassis has no sharp corners so this is not a serious issue. Still, it would be a shame to scratch it.
  • Now place the chassis down on a flat, clear surface. Take care not to damage the sensor on the top of the unit (probably facing downwards since it’s the side opposite the handle).
  • Push the handle in all the way and let go. It should stay in place.
  • Turn the case, so that the sensor is now facing upwards.
Chassis exposed
Removing the drive heatsink:
  • Locate and remove the three Torx bolts which hold the drive hatsink in place as shown above. Note that the bolts are captive, and as such do not actually come out. This is a great Apple design point, since it stops the bolts from falling into the machine!
  • Now lift out the heat sink itself.
Lifting out the drive heatsink
Removing the drive:
  • Locate the airport card flap on the side of the unit.
Opening the Airport door
  • Open the Airport door. It will swing out. Don’t worry, it’s well hinged and won’t fall off!
  • Remove the drive power connector – Mine was stuck firmly and required pliers to release it!
Remove the power connector with pliers
Removing the drive power connector
  • Now remove the ATA connector.
Removing the drive\'s ATA (data) connector
  • The drive should now slide out from the opposite side of the chassis.
Sliding out the drive
  • Remove the guide rail from the side of the drive.
Remove the guide rail from the side of the drive
Replacing the drive:
  • Don’t forget the plastic drive guide rail
  • Slide the drive back in. 
  • (Optional) You may want to coat both sides of the three steel posts which hold the drive with a drop or two of heatsink compound, since new drives run much hotter than the old 20GB drive that was in there and every bit of cooling will help.
Add a few drops of heatsink compound to the drive supports
  • Replace the bolts which hold the heatsink.
  • Replace the data and power connectors.
  • Close the Airport card door. Make sure the airport antenna cable  is taped  firmly to the door if you don’t have an Airport card installed.
  • Put chassis back in case, connect and power up. 

 

Categories: Mac, mods, Technology Tags: , , ,

Installing a fan in the G4 Cube

April 18, 2008 2 comments

Many Mac purists out there will shake their heads and disagree vehemently, but with spares for the remaing cubes starting to thin out, a fan is essential in keeping your cube healthy, and I heartily recommend one to anyone who uses their cube for more than a couple of hours a day.

The Mac G4 Cube was designed to hold a fan. Even though in it’s original incarnations (450MHz and 500MHz varieties), there was no fan installed, the case itself has a place to hold an 80mm fan of about 20mm thickness and with a little effort, one can crowbar a 25mm thick fan in for more effective cooling.

Be careful when selecting the fan. The one I bought was a silent, solidly built one which had supporting tubes around the corner mounting holes. It seemed like a good idea at the time. However, these turn out to make installing the fan without disassembling the whole case impossible. A lighter fan without supports on the corners would have been much easier to install. In any case, I used a hacksaw and cut two adjacent supports along the edge which eventually ended up towards the back of the Cube.

Three common types of fans

I bought myself a nice, quiet 80mm x 25mm 1900 RPM fan. They tend to be about 3~6db quieter than 20mm fans which push the same amount of air. It came with 3 wires, red, black and yellow

Replacing the fan is actually a little more time consuming than replacing the hard disk, but not really much more difficult.

You’ll need a set of Torx drivers for the star shaped “security” screws. Sizes T8, T10 and T12 should do the trick. You will also need a medium sized pair of pliers for some minor and painless case modifications.

Opening the case:

      First make sure you have the fan, the torx drivers and enough room to work on,  i.e. a flat, clear surface within easy reaching distance.

  • Unplug the Cube and invert it. Take care not to scratch the machine’s plastic case. I inverted mine onto a pillow.
  • Push the rectangular, inset bar located on the upturned base in firmly, until you hear it click. Now release it. The handle should pop out.
  • Use the handle to lift the chassis out of the upturned case. If this is the first time it has been removed, it might take a little teasing to get things moving.
  • Lift the chassis out vertically, taking care not to scratch the insides of the case with the metal corners of the chassis. The chassis has no sharp corners so this is not a serious issue. Still, it would be a shame to scratch it.
  • Now place the chassis down on a flat, clear surface. Take care not to damage the sensor on the top of the unit (probably facing downwards since it’s the side opposite the handle).
  • Push the handle in all the way and let go. It should stay in place.
  • Turn the case, so that the sensor is now facing upwards.
G4 Cube and Fan

Opening the chassis

In order to put a new fan in without a complete disassembly, it is necessary to remove the optical drive.

  • Remove the top plate by taking out the four corner bolts and two bolts on either side.
Remove these eight bolts
  • Lift off the top, slowly and remove the small cable which connects the power sensor to the chassis.
  • Place the top panel somewhere level, avoid touching the sensor.
  • Now slide the plate with the orange spot on it slowly up and out, revealing the optical drive.
Removing the optical drive cover
You should now see the drive exposed as the picture below shows. 
  • On either side of the drive, there are some screws, holding it in place. Remove these screws on the sides of the optical drive to release it.
  • Slide the drive upwards and remove the power and ATA cables from the connectors.
Removing the optical drive
  • The drive can now be removed, revealing the gap at the bottom of the case for the 80mm fan.
Space for the fan
Installing the Fan
  • In order to slide the 25mm fan into the case without disassembling the whole thing, we need to bend the fan supports out to the sides until they allow the fan to slide in.
Bend the fan supports
  • Note that there are two further holders at the rear of the case which may prevent your fan from fitting.
  • If your fan has corner posts around the holding bolts, remove two of them to allow the fan to slide into place. 
Three common types of fans
  • Bend the supports back around the fan to ensure a snug fit, as shown in this example picture below.
Fan support bent around to hold the fan
  • After playing around with the supports for a bit, I taped around the fan with duck tape after breaking the two back posts. This also helps reduce vibration noise, but this is not necessary.
Connecting the fan to the power

It’s now time to connect the fan to the power supply. We will use the optical drive’s power supply which we have at hand since we removed the optical drive.

  • Remove the little cover from the back of the optical drive’s power connector.
  • You should see four cables leading into the connector.
Connector Closeup - after removing cap

This big connector has the ability to generate 3 different voltages, 5v (slowest), 7v and 12v (fastest). Depending on your noise tolerance and the power and voltage rating of your fan, you may find any one of these three voltages suitable. This I will leave for you to experiment with.

Note, if your fan has three wires, one of them is unnecessary for this modification. You will have to determine which two wires (usually red and black) are the power wires and which one connects to the sensor.

The table below shows how to harness any of three voltages from the optical drive’s chunky 4 pin power connector. 

 

Fan Wire 1 (Black)

Fan Wire 2 (Red or Yellow)

Fan at 5V

Molex Ground (Black)

Molex +5V (Red)

Fan at 7V

Molex +5V

Molex +12V (Yellow)

Fan at 12V

Molex Ground (Black)

Molex +12V (Yellow)

For example, to run the fan at 7V, connect the fan’s black wire to the +5V (Red) connection and the fan’s red/yellow wire to the +12V (Yellow) connection. You can connect the fan’s RPM wire directly up to the motherboard. Unfortunately, on the Mac, the wires are all black! Check the photo to confirm the voltages.

Connector Voltages

  • Cut the power cables of the fan to a decent length, you won’t need the connector. You can discard the sensor wire on a three wire fan.
  • Use a knife or other tool to push the cables strongly into the drive’s connector without damaging the metal “blades”. These blades should cut through the rubber insulation on the cable and create a connection with the copper wire itself.
  • If the cable comes out, your fan will stop. This will be very difficult to spot later, unless you install a fan with an LED or other indicator, so confirm that the cable is tightly held before reassembling the computer. 
Closeup of a connector with fan connected.
  • Don’t forget to replace the plastic cover.

Putting things back together

  • First the optical drive’s data and power cables.
  • The optical drive’s holding screws.
  • The power button’s wire connecting the top plate to the chassis.
  • The chassis top plate with its 8 screws.
  • Upturn the chassis carefully and pop out the handle
  • Carefully return the chassis to the case, making sure not to catch anything, and push the handle in all the way until it clicks.
  • Turn the computer over, connect it up and restart.
  • Confirm the fan visually, by listening or by holding your hand over the top vent.

Congratulations, your Mac G4 Cube just got even cooler!

Categories: Mac, mods, Technology Tags: , , , ,

Directly Install a shop copy of Leopard on an iMac 700MHz (or even a stock, unmodified G4 Cube!)

March 21, 2008 4 comments

imacg4-leopard

Yes, despite Leopard being limited to 867MHz G4 processors and faster, you can pretty much install Leopard on any G4 Mac with an AGP graphics card. (OK, so the picture above is a phtoshopped image of a 1GHz model, but you get the idea.)

So, I decided to try it out and reinstall Leopard from scratch on my shiny “new” iMac with its rip-roaring 700MHz processor, 40GB hard disk and 640MB RAM.

To cut a long story short, it can be done and ridiculously easily!

  • Reboot the iMac
  • Hold down the Cmd-Opt-O-F keys. Instead of the usual white screen and grey Apple logo, you’ll get a black screen with a white Open Firmware prompt.
  • This is NOT a regular BASH prompt, so don’t be tempted to try anything!
  • Insert the shop copy of the Leopard DVD. (If it’s already in the drive, that’s fine, too).
  • Type the following lines in exactly as shown below. After pressing Return, you should see “ok” to signify that the command was understood. If at any time you have any doubt, just reset the Mac and start again since these settings are cleared after a reboot.

For your iMac, G4 Cube etc, type this:

dev /cpus/PowerPC,G4@0
d# 867000000 encode-int " clock-frequency" property
boot cd:,\\:tbxi
  • The install will continue.

I haven’t tried this below, but…
If you have a dual CPU computer, use the following:

dev /cpus/PowerPC,G4@0
d# 867000000 encode-int " clock-frequency" property
dev /cpus/PowerPC,G4@1
d# 867000000 encode-int " clock-frequency" property
boot cd:,\\:tbxi
  • The install will continue.

Remember this hint does not confer any magical speed increase, it just lies to the Installer! Also, a reboot clears this tweak, But Leopard will continue to run, once installed.

Obvious point but… If you install a new OS, you’ll in all likelihood LOSE SOME OR ALL OF THE CONTENTS OF THE DRIVE. BACKUP FIRST!

Categories: Mac, Tech Tips, Technology Tags: , , , ,

Upgrading iMac 15″ flat panel (iLamp) Hard Disk, DVD Drive and Memory to the full 1GB

March 20, 2008 1 comment

I was thrilled to see just how well Leopard ran on my new 700MHz iMac 15″ flat panel LCD with the user upgradable RAM increased to 640MB and the stock 40GB hard disk.

So, I am really looking forward to seeing the performance and how the thing performs with a full 1GB of RAM (considered minimum for OS X 10.5 Leopard to run smoothly. I suspect that it will be 100% usable, not a “poor” or “barely ok”, but a full on “nice” or at least, “not too shabby.” 

Firstly, You will need a nice set of tools to get inside the iMac, it’s a bit of a fiend to open, along the lines of the Mac Mini, but with more screws! Not impossible, but not trivial.

First Up, make sure you have all the components you need

  • 3.5″ PATA (Ultra ATA 66) HDD. There is no space for a SATA-PATA converter, so get the real deal.
  • A Mac Compatible DVD Writer (preferably one with iDVD support).

NOTE: The DVD writer should be less than 19.5cm deep since that’s the size of the drive that’s in there. The tray bezel should also be removable.

  • 512MB, PC133 (133MHz) 168 pin DIMM.
  • 512MB, PC133 (133MHz) 144 pin SO-DIMM 

Before you start make sure that everything is ready:

  • YOU WILL NEED SOME HEAT SINK COMPOUND (Thermal paste).
    I’m shouting this because this is easy to overlook and WILL turn your iMac into a paperweight if you forget it.
  • A set of Torx drivers, a number 10 and a number 15 should do the trick, but don’t quote me on that! Better off having a whole set from 6 to 20.
  • A Plus head screwdriver. I have no idea what size, just look at the screws and be the judge 🙂
  • A wide open, well lit space to work, covered in a soft duvet, pillow or stack of towels.
  • Somewhere to earth yourself or better yet, a grounding strap.
Prepare your iMac for surgery:
  • Unplug your iMac completely.
  • Clean your iMac. Stray dust WILL somehow find a way to scratch your screen at the first opportunity.
  • (optional) You might want to wrap the screen in a soft, clean towel and pin it with safety pins.

 Removing the user accessible parts of the iMac.

  • Unscrew the base screws with the plus-head screwdriver.
  • Remove the RAM and Airport card, if present.
 
Removing the base
  • Remove Torx bolts holding base together.
Remove base screws
  • Now remove the base, carefully, prising the bottom off. 

Important: Try not to twist or bend the base in relation to the top. Work your hands around the base, gradually easing the base away from the top. At all times, keep the base parallel to the top until it is clear of the connectors.

Pull the base off the iMac
  • Now the base is off, you may, depending on the way your iMac is being supported, need to detach some or all the cables which hold the base to the top. There are six cables, see the diagram below.

Disconnect iMac base

Make sure you can remember where each cable goes. Also, the green earth cable on the left hand side is secured to the top with a Torx bolt that needs to be removed.

Replacing the internally installed (non-user-serviceable) RAM

The RAM slot is visible at the bottom of the above picture and can now be replaced.

Make sure you replace it with a decent, “full-size” (desktop) 168pin 133MHz SDRAM chip. 100MHz chips tend to cause kernel panics, avoid them!

  • Push the two cream coloured tabs out and down and the DIMM should pop up. Pull it out vertically.

Replacing the internal, full sized DIMM

  • Now might be a good time to use an air blower and clean out the RAM slot.
  • When replacing the DIMM with a new one, make sure you push it in vertically, all the way to the bottom. The two cream coloured tabs should automatically pop into place.
  • I’ll repeat the bit above, make sure you push the RAM in vertically, all the way to the bottom. If you don’t you’ll be reopening your case again sooner than you’d like.

Removing the drive assembly.

Next we are going to remove the drive assembly which holds the hard disk drive and the Combo DVD Drive.

  • Remove the copper tape that holds the electromagnetic shielding from the front of the drive and the two bolts shown below.
  • Gently pull the shielding away from the top and put it aside.

Remove iMac EM shielding

  • Now remove the four bolts that hold the drive assembly in place.
  • Make sure there are no cables tethered to the drive assembly. If there are, you will need to cut the cable-ties and release them.
  • Lift the drive assembly away from the top.

Remove iMac drive assembly

  • Once the drive assembly is out, remove the power connectors from both the HDD and DVD.

The data connector is lodged between the two drives and cannot be removed.

The HDD is covered with a sticky backed film, probably an interference reducing tactic. This film will have to be removed before we can remove the HDD from the assembly.

  • Carefully peel off the paper.

 

Remove sticky paper cover

  •  Remove the eight bolts which hold the hdd

Remove HDD and DVD bolts

 

  • Lift out the HDD
  • Slide out the DVD drive, connector first (i.e. backwards)
  • Make note as you do so where the fronts and backs of of each drive sit!

Disassembly Complete:

Read the remainder of this post for some critical tips and then work back through this post in reverse if you need to look at the photos.

  • Replace the drives in the assembly, making sure the ATA cable is between the HDD and the DVD drive before tightening anything.

Drive assembly checks:

Before reassembling, confirm the following:

  • HDD is set to Master and the DVD is Slave or as Apple recommends, use Cable Select for both drives – If this is not done, you will find one or both of the drives inaccessible.
  • The drives are aligned properly and are the right way around!
  • The DVD drive fits – Some are deeper than others!
  • Before you screw the drive assembly into place, make sure you have reattached the ATA connector and the power connectors to both drives. Trying to reconnect the cables after bolting the drives in place is a futile waste of time. (Talking from experience!!)
  • Make sure the appropriate wires run behind the drive assembly before the drive assembly is replaced, since routing the wires around the side may interfere when closing the case. 
  • The DVD bezel on the tray is small enough to fit though the white drive flap on the front of the iMac.

You may need to remove the new DVD drive’s whole front plastic panel and/or the plastic bezel on the front of the drive tray.

  • You will need to remove the bezel first: use a pin, piece of stiff wire or a paperclip to poke the little hole at the front of the drive and release the tray. Behind the lip of the tray, there should be a couple of clips holding the bezel to the drive tray.
  • Now, the drive front panel can be removed (usually, depending on your drive). There are typically four to six holes in the metal casing of the drive, near to the front panel, form which protrude short plastic posts. Pushing the posts in with a screwdriver one by one should release the front of the drive.

Reconnecting everything:

The CPU heatsink is connected to a heatpipe which runs along the bottom of the case from the CPU to a junction, which transfers the heat from the CPU into the upper-half of the base to be cooled by the top mounted fan.

iMac Heat Pipe Bottom

  • Scrape of the old heatsink compound and thoroughly clean and polish the post without filing or reducing in any way. You may need acetone or metal polish. A plastic scraper may also help remove the old gunk which may have hardened due to heat.

iMac Heat Pipe Top

  • Do the same for the top part of the junction.
  • Apply a thin, neat coating of heatsink compound (thermal paste) to either one -not both- of the posts.
If you do not clean the junction properly or forget to apply the heatsink compound, your iMac will freeze, crash and perhaps suffer irreparable damage due to the CPU overheating.
  • Now connect all the wires back up. 
  • If necessary, restrain the cables against the side of the drive assembly to prevent from getting trapped when resealing the base.
  • Align the two halves of the case.
  • Ease the base on, making sure the rear connector is fitting snugly before tightening any bolts.
Do not attempt to run the iMac until the four base bolts are back in place. One of them is used to squeeze the two halves of the heatpipe together, without which the heat won’t transfer away from the CPU and you computer will malfunction.
Mission accomplished.
Categories: Mac, mods, Technology Tags: , ,

Installing Leopard on iMac 700MHz with Target Disk Mode

February 13, 2008 Leave a comment

I’ve seen a lot of talk about Leopard requiring the latest system just to get it running. So I’m writing to put that myth to sleep.

So, I decided to upgrade the RAM and the OS to either Tiger or Leopard and test the machine with original 40GB hard disk and just an additional 512MB upgrade (for a total of 640MB). If it ran Leopoard tolerably fast and stable enough then I’d make Leopard permanent and upgrade to the the full 1GB RAM, a Bigger Hard disk and a DVD-R, which should provide even better performance. If not then I’d fall back to Tiger rather than Leopard.

Preparing the iMac for the Leopard install.

This was trivial and involved adding a 512MB, 133MHz SODIMM RAM module.

    See the Upgrading the iMac’s RAM to 640 MB post.

  • Next, I rebooted the iMac and tested the memory. All was well.
  • Restart the iMac in Firewire Target Disk mode by holding down T until a few seconds after the chime.
  • I used Firewire target disk mode and CCC to clone the HDD off Tomoko’s 12″ PowerBook Leopard install. This took about an hour for the 10GB or so transfer.

Booted up fine, first time.

Gotchas

After removing various settings for Bluetooth, Airmac and changing the network settings so as not to double up with the PowerBook, I got to work testing.

I was surprised at the performance, expecting it to be slower than it was and the 1024 x 768 screen to be more cramped. But it runs quite well. I tried Safari, Word, Excel and Mail at the same time (a typical day’s work) and found the machine to be pleasant and entirely usable if not amazingly fast. There were none of the annoyances that I have with Tiger on my stock G4 Cube, for example.

I found that the 10.5.2 system install was waiting so I installed that plus graphics update 1.0 and a few other queued updates.

Probably subjective, but I found the whole thing to be even smoother and more responsive. For example, clicking on the finder icon in the dock brings up any open finder windows almost instantaneously over whatever you’re doing at the time.

A lot better than my stock cube with 1.5GB RAM and Tiger.

I’d like to test it out with Tiger for a speed comparison, but quite frankly, besides the lack of awaking from sleep, it’s running so smooth that I don’t see the point.

In conclusion

  • Install from cloned PowerBook HDD using CCC was effortless and took an hour or so for a 10GB install. 
  • Leopard runs trouble free, with so far no crashes or random stuff happening (apart from wake from sleep).
  • 10.5.2 upgrade and Graphics Update 1.0 work wonderfully.
  • 640MB RAM and 40GB HDD gives more than adequate performance for Surfing, iTunes, Office 2004 multitasking.

    Remaining Niggles:

    1. Awakes from sleep with screen artifacts (but at least it can be gracefully reset since the OSX10.5.2 / GU1.0 updates).
    2. Boot up is slow. Haven’t timed it, but it’s slow.
    3. Logging in is slow.

      Of the above complaints, only the first is a real one, since, once logged in, everything is hunky dory.

      I think I’ll keep the machine like this for a week or to so that I can appreciate the upgrade when I perform it.

      I wonder how much faster the Seagate 500GB HDD and extra 386MB of RAM will make it…

      Categories: Mac, Tech Tips, Technology Tags: , , , , ,

      Upgrading iMac G4 to 640 MB.

      February 12, 2008 Leave a comment

      The iMac G4 is unique, as far as I’m aware, in that it has two memory slots which take different types of memory. One slot is easily user accessible with nothing more than a screwdriver and takes a 133MHz laptop SO-DIMM, up to 512MB.

      The other comes factory preinstalled (in this case with a 128 MB, 133MHz DIMM), but is much harder to access, requiring disassembly with a set of Torx (star) drivers.

      Upgrading to 640MB, then, is a simple task requiring about 5 minutes.

      You will need:

      • A large area with soft padding to support the iMac in a lying down position.
      • A small, cross-head (plus) driver.
      • A branded 512 MB, 133 MHz, SO-DIMM for a laptop, preferably with a compatibility replacement guarantee, should things go wrong.
      let’s get started:
      • Turn the iMac on its side. Take special care not to scratch the screen or the computer’s plasic casing.
      • Locate the four screws on the base and unscrew until loose.
      iMac, getting the base off
      • Carefully remove the beautifully crafted aluminium base plate, revealing the RAM slot.
      • Ground yourself on something metal, like a metal door sash, a large metal desk or the kitchen sink.
      • Carefully insert the 512MB RAM stick in the slot at about 30 degrees angle from the base. Push the long edge very firmly, sliding the chip into the slot. 
      With iMac open, insert the RAM.
      • Make sure the gold contacts are well in contact with the slots pins. When you are sure it is seated firmly, press down on the flat side of the chip until it is level with the base of the computer and the little tabs on either side clip into place.
      Inserting the RAM properly
      • Make sure the chip is held firmly and the clips are properly clasping the chip.
      • Replace the lid.
      That’s it. Power on and check the Apple menu, and About This Mac to confirm the memory.
      You should test the system over night with a memory checker. I recommend:
      Rember by Kelly Computing
      You should now have an iMac with 640MB of RAM.
      Categories: Mac, mods, Technology Tags: , , ,