Step One: Getting Started

The beginning of an iBook 200l overclock. Left: Carl & Stan planning the resistor transfers. Centre: The tools of the trade. Right: Carl's iBook pre-OC.

To get started with disassembling and overclocking your iBook Dual USB, make sure you have some soldering skill and a lot of courage - there are some things in this world that are better left untouched, and in retrospect, this is certainly one of them. The tools we use are in the photo above. A preliminary list (off the top of my head) is something like:

- External USB keyboard and mouse (for testing later)
- Toothed pliers for grabbing slippery bits, flat pliers for working with shielding metal
- Magnet for pulling out hard-to-reach screws
- Assorted Phillips-head and flat-head jeweler's screwdrivers
- Allen wrench of appropriate size for bottom case screws (metric - 1.5 mm - 2.5 mm, I think)
- Prying tool for taking off bottom case (we use alternately an orange peeler or the Swiss Card nail file you see in the photo)
- Tweezers for reaching difficult screws
- X-acto knife for cutting tape
- Digital multimeter to check solder joints
- Low power soldering iron (15 W is ideal - 12 W might even be better if you can find it)
- Solder flux (don't actually use this for soldering - just to clean iron)

Once you have assembled all the tools, find a well-lit working area and set the iBook on a soft (static-free!!!) cloth. We just used a bed sheet, but we made sure we washed it with a Bounce sheet first. Lay everything out where you know you will be able to find it, and then shut off your iBook and turn it upside down.

Step Two: Removing the Bottom Case

Left: iBook upside down with battery removed. Right: Removing iBook feet.

First take the battery out of the iBook and set it somewhere away from your work area. You won't be needing it again until after the project has been completed. Then pry out the three remaining rubber feet using one of the flat-head jeweler's screwdrivers.

Removing screws from bottom case.

The next step is to remove the screws which are holding the bottom case down. There are 8 of these. Three Phillips-head screws can be found underneath where you removed the rubber feet previously. There are also three Allen-head screws to be removed - the short one is from smack-dab in the middle of the iBook. The last two screws are also Phillips-head, and are located in the battery bay, right beside the battery connector. (See middle photo above).

To keep track of the screws we've removed, Stan and I stick them all to a piece of masking tape and mark the locations beside them on a sheet of scrap paper. You'll have to remember where all of the screws came from so that you can put them all back again later.

Prying off the bottom case.

Now that all of the screws holding it down have been removed, it is time to pry off the white plastic bottom case. Start with the catch inside the battery bay (above, left). Then work your way around the case using a prying tool of some kind (above, centre), but be careful not to damage the case. Some of the catches here take a pretty hefty amount of force to remove, so don't be too shy about it. The rightmost photo above shows the entire case almost removed. Make sure you take the two small springs out of the battery bay after the case is removed so they don't get lost later on. Don't forget to put them back in there, though.

Screws to be removed to take off RF shielding (click for marked closeup).

The next step is simple - just peel off the tape holding down the RF shielding plate, and remove the 5 screws marked red in the photo above (purple screws come later). You may need to use the X-acto knife to slice the metallic tape away on the side nearest the ports. When the shielding plate is removed, put it somewhere safe for the time being.

Step Three: Soldering, Part I

Underside of the iBook with shielding metal removed.

Click on the above image to see the areas on the logic board that we'll be working with. To go from a 66 MHz bus to a 100 MHz bus, we need to move the 4K7 resistor from location R341 to R340. You most definitely will want to do this, as it will work on every machine with a 100% success rate if you have PC-100 RAM or faster. The increase in bus speed will be the biggest change for your machine, and will be the most noticeable performance increase from these modifications. However, since the iBook began life with a 66 MHz bus and a 7.5x multiplier, we need to move to a smaller multiplier to avoid trying to push the chip at 750 MHz (which it most certainly will not do). So, off comes R271, as well. R271 is needed for none of the 100 MHz bus multiplier options.

Finding R340 and R341. I'm pointing at R341 in the picture - I don't think you can see the label for R340... it's behind my screwdriver.

These are 4 images to help you see R271 and how to remove it. Note that these are all 0 Ohm jumpers - don't mix them up with the R34X resistor!!!

After you've moved R341 to R340 and removed R271, you're done with the bottom side of the logic board. You can put the RF shielding back on, but don't put the plastic case back yet. You should probably keep R271 in a safe place in case you wreck something on the top side of the logic board you can use it to fix the problem. If you do a good job everywhere else, it makes a good memento of the overclock job.

Step Four: Removing Palmrest

Left: Click image for closeup. Centre: CD Bay screw #1. Right: CD Bay screw #2 (aka - The Bitch Screw).

Now you have to take out the screws which hold on the palmrest of the iBook. The purple screws in the leftmost image above need to be removed, as do two tiny screws in the CD bay. The CD bay screws are more difficult to get at on a combo drive model (pictured), but easier on a DVD model. Good luck in either case. This is where the tweezers and the magnet came in handy. Once these screws are removed, flip the iBook right-side up and open it up.

Left: Detaching the keyboard ribbon cable. Right: Detaching the trackpad ribbon cable.

To take off the palmrest, you have to first take off the keyboard. Flip the keyboard over and remove the AirPort card, the RAM plate, and any RAM you might have installed. Then use one of the flat head screwdrivers to unplug the keyboard and the trackpad ribbon cables and then take off the keyboard entirely.

Screws to be removed in order to take off the trackpad and palmrest.

The photograph above has circled in red the screws you need to remove to take off the trackpad. The screw with the magnet on top of it is slightly shorter than the other three - make sure it goes back in the right place later, with the magnet back in place on top of it.

Removing the palmrest and trackpad. Left: Take this corner off last. Left Centre: Gently lift up on the palmrest. Right Centre: Unplug the power button. Right: Also unplug the speaker wires.

Now that the palmrest is completely disconnected, gently pull up on it and remove it from the rest of the computer. There are two "sticking points" here. The first is near the display hinge where the power button is plugged onto the logic board. Use one of the screwdrivers to pry up the plug. Flip the palmrest over to the left of the computer and then use the screwdriver to unplug the speaker wires. Then take the palmrest and put it somewhere safe.

Step Five: Removing Top RF Shielding

RF Shielding Screws - Part the Second

Circled in the photo above are the screws that must be removed to take off the iBook's top RF shielding. There are lots of them here, so be careful. The four screws around the battery bay are very small, but one is smaller than the others. This one goes right in the corner of the battery bay, and is circled in purple. Screws circled in red are interchangeable, as are those circled in yellow. Yellow screws are big ones. The green screw is one-of-a-kind, and must be removed as well. The cyan box marks the spot where the AirPort antenna plug should come out - watch this during reassembly. Be careful with the metallic tape at this stage too. Peel it off carefully and then replace it later.

Pulling up the RF shield. Watch for the plate catching in the back left corner (right side photo).

With all the screws out and tape removed, you can now remove the RF shielding plate. Take it off carefully and put it somewhere for later. The machine should look like the photo below:

iBook with RF shielding removed.

Step Six: Hard Disk Replacement

You'll have to follow these steps if you want to replace the hard disk in your machine. We recommend not doing both a HD replacement and an overclock job in one fell swoop. If you do only one at a time you'll cause yourself less problems in the testing phase of the modification. If you plan on doing only a HD replacement, you won't need to take off the bottom RF plate like we did above, and you certainly won't have to do any soldering. If you are doing an overclock, you still may want to take out the hard drive, as the brackets can get in the way of dealing with the heat sink (below).

Hard disk removal. Left: Unplug the disk cable. Centre: Unplug the power cord. Right: Remove brackets.

First up is to unplug the disk cable from the logic board. Once it's taken off, also unplug the power cord in the front left corner of the machine. At this point you should be able to remove the disk from the machine. Also unplug the hard disk cable from the disk itself. The mounting screws on the hard disk are size T-9 torx. Take them off and put them on the new disk. Also transfer over the black plastic shield and the black tape. You can now install the new hard disk and reassmble the machine if that was your goal.

Step Seven: Under the Heat Sink

Left: The last screw. Interestingly enough, this little guy is visible after the whole machine has been put back together. Right: bending the heat sink out of the way.

The next step is to get the processor heat sink out of your way so that you can finish the overclocking job. Remove the last screw as shown above in the left photograph, and then bend the heat sink plate up and away from you tomake room to work underneath. Try not to kink the hollow copper tube - it's what takes heat from your CPU to the vent on the back of the machine. In a couple of the machines we've overclocked, this copper tube was easier to bend than on others. Your mileage may vary, of course. Once the heat sink is out of the way, your machine should look like this:

Completely disassembled iBook - ready for the last step.

Step Eight: Soldering, Part II

Which resistors to solder? They're boxed in red on these images (click to see larger).

This is the last soldering step for your iBook overclock job. I'm going to assume that you're going from a 500-400/66 machine to 600-350/100. This is the most common, and easiest OC job to do. Our standard practice is to move the jumper from R43 to R45, and then move the jumper from R44 to R57. If you want to make your machine 600-400/100, you also need to take the jumper you removed from R271 and move it to R56. Below is a table (click to download PDF) of possible locations for jumpers and speed options. (NB - the low clock speed can be used in Mac OS 9 by selecting the "slow down processor" option in the Energy Saver control panel).

Table of Resistor Locations for Overclocking (click for PDF)

There may be some machines out there that can handle running at 650-350/100. To do this, you'll need to set your machine up as above for 600-350/100, but instead of moving R43 to R45, leave it in place and use the jumper from R271 at R45. Make sure you test your machine for a good while to see if this is useful. Mine ran at 650 for about a half hour before becoming obviously unstable.

One of the five overclocked machines we've done could not run at 600-350/100 either. We backed it down to 550-400/100 and it's now working fine. There is no noticeable speed difference between the 600 MHz machines and the 550 MHz machine (proving that bus speed is the biggest difference). To set a machine up for 550-400/100 you need jumpers at R45, R57, and R270, so you'll need to open up the bottom of the machine again. Should your machine be capable only of 500 MHz, you'll need only R57 and R270.

Once this soldering is done, screw the heat sink back down snugly to the processor, and move on to the testing phase.

Step Nine: Testing and Reassembly

Left: Turn on your computer without a power button. Centre: Another look at the switch. Right: Successful overclock!

For testing, we use an external USB keyboard and mouse. Plug them in (and your AC adapter), and then use one of the flat head screwdrivers to turn on the machine. Remember - you don't have speakers attached, so you won't hear the choir of angels you're expecting. We sometimes also plug headphones in to hear that reassuring sound. Let the machine boot up and then play around with it for a while to make sure nothing gets crashy. We usually test for about 10 or 15 minutes of hardcore stuff - playing DVDs, iTunes visualizer, compiling code, etc. Anything to get the processor working hard. If all is well, you can reassemble the machine (go backwards through the above steps) and you're done the hard part! If things aren't so good, go back to step eight and try a slower speed setting.

Step Ten: Open Firmware Hack

At this stage the overclock is completed. We noticed on earlier versions of Mac OS X (pre 10.1.2) that the machine displayed odd behaviour without reconfiguring the open firmware of the iBook to note that it now has a 100 MHz bus and a 600 MHz processor. Also, Apple System Profiler in Mac OS X will report an incorrect clock speed if the OF script below is not entered. Here are the steps for doing this modification:

1. Reboot the computer holding down Cmd-Opt-O-F to enter the Open Firmware command line.
2. Type nvedit and press Return
3. Enter the following script exactly, pressing Return at the end of each line.

" /" select-dev
5efc680 " clock-frequency" get-my-property 2drop !
" /cpus/PowerPC,750@0" select-dev
239ea700 " clock-frequency" get-my-property 2drop !
5efc680 " bus-frequency" get-my-property 2drop !
17bf1a0 " timebase-frequency" get-my-property 2drop !

4. Press Ctrl-C to exit the editor.
5. Type nvstore and press Return
6. Type setenv use-nvramrc? true and then press Return
7. Type reset-all and press Return

Now your machine should behave as expected.