A brief guide to replacing the hard disk in a G4 cube
A few notes before going into any details:
Why replace the disk?
I recently purchased a cube, and love working on the machine for a variety of reasons. It's small and quiet, the 15" flat panel display is easy on the eyes, the cabling is tidy, the Airport systems happily shares my cable modem internet connection, it comfortably meets all my work needs. My cube is equipped with the 450Mhz G4 processor and a DVD-ROM drive. I've also got Soundsticks and a Lacie 16x10x40x Firewire CDR connected. I've been wanting to get my hands on a Unix system I can live with on a daily basis, and while there's significant room for improvement, MacOS X is exactly what I've been waiting for.
When the price of memory dropped recently, I took the opportunity to put three 512Mb DIMMS in the cube. Equipped with the maximum 1.5GB of memory, the performance is excellent. It seemed a shame to be stuck with 20Gb of storage and a disk whose performance appeared to be mediocre.
I decided that I wanted to replace the disk, and read some very favourable reviews of the new IBM 60GXP disks at Storagereview. I purchased the new drive from Scan, they had the item in stock and delivered the next day. Most IDE disks are roughly equivalent in size and the positioning of connectors, so I guessed that it would be possible to swap the cube's unit for something better.
Tools
If you've ever removed the cube core to add memory or an Airport card, you may have noticed the kind of bolts used for assembly. They're similar to Allen bolts, except the recessed bolt heads are more pointed in the corners, making a "star" shape. These are often referred to as "anti-tamper" screws, and it's entirely possible that you don't have a tool suitable for accessing the cube's innards.
When the hard disk arrived I went down to my local hardware store, which turned out to have an extensive selection of equipment. It turns out that you need a "T10" size tool for the majority of the cube's bolts, and a "T8" tool for the heatsink connected to the hard disk. If I had a digital camera, I'd put some pictures in here to demonstrate...
Disassembly
You'll probably spend half an hour in total, fitting the new disk. Take it nice and slow.
You'll need to lay down some soft cloths on a suitable table, make sure the cube is shut down, then lay it upside down in front of you. Remove all the cables, and extract the core by pushing the handle downwards as per Apple's instructions. Carefully lift the core onto a cloth and get ready to start removing bolts. Put the outer case out of the way so it won't get scratched while you're moving things around.
Examine the location of the disk. You'll notice that it's quite central, and that there's a black heatsink attached to one side by three small black bolts. The opposite side is difficult to see clearly, as your view is obstructed by various other components. You'll notice that near the battery, there's another bolt visible. There are two on this side, and they are completely inaccessible. Fortunately, somebody at Apple has thought about this....more on that later....
You'll need to get to the three screws on the heatsink, and to do this you'll need to remove the silver metal frame that acts as a sort of lid for the enclosure. All the grey external bolts require a "T10" size tool. Be particularly careful of the power switch sensor, as it would appear to be quite fragile and I'd recommend avoiding any kind of contact with it.
You'll need to remove all of the bolts holding the "lid" in place. Most of them are on the external face, with a couple of longer bolts located centrally on two of the square's sides. You'll notice that there are some metal plates and fins that lock into the "lid". when you come to remove the top plate. The cube's internals may shuffle around a bit when you remove the "lid", as the interlocking plates appear to make the structure more rigid. Also, be careful removing the lid as there is a short flexible cable connected to the power switch sensor. When you have undone all the bolts, you will be able to rotate the metal plate around and remove the small white connector block from the power sensor. You can now put the plate aside, minding the switch/sensor and take a closer look at the hard disk.
At this point, you may find that the four corner pillars of the cube are free to wobble and move around. They are no longer held in place by external bolts, so you can remove them from their mountings if you want to avoid damaging them during further handling.
At this point, I went a bit further than is necessary and started removal of another plate or two to gain better access to other areas of the cube. This probably isn't required, and I'll explain why... Apple have only actually bolted the hard disk to the chassis on one side. The smaller black "T8" screws holding the black heatsink in place also successfully pin the hard disk to the rest of the chassis. These three screws on the heatsink are the only bolts that are actually holding the disk in place, the other side of the hard disk is actually mounted in a groove. Two bolts, barely visible and not accessible from the other side, actually bolt a railing to one edge of the hard disk. This rail fits into a groove on the chassis, and helps to hold the disk in place. This ingenius piece of construction actually makes the whole process of swapping the disk a lot easier than it would otherwise be.
Before removing the heatsink screws, go to the other side, and open the "swing door" for the airport card. Underneath, you will see a power connector for the hard disk and an IDE ribbon cable. The power cable is quite a tight fit, and requires a carefully controlled struggle to get free. This is quite an awkward operation, and you need to take care not to damage the fragile door of the Airport card while you are doing it. You can then remove the IDE ribbon cable connector using the white plastic tab that is there for this purpose.
All you need to do now, is remove the three screws from the heatsink., and you will be able to push the disk out sideways from the end with the connectors. Once out, you will be able to examine the rail bolted to the side of the disk. If you remove the two bolts on the rail, it comes off, and you will now have the 20Gb Western-Digital hard disk in your hands.
Installing a new disk
Insertion of the new disk is pretty straight-forward. I didn't need to change any jumper positions on my IBM disk, it was set to act as the master device straight from the factory. Bolt the rail onto the correct side of the disk. slide the new disk into the chassis. Locate the heatsink, align with the screw holes then put the three black bolts in place. Reconnect the power and IDE cable. Close the Airport swing door.
You then need to replace the corner pillars if you took them out. You will need to reconnect the power-sensor cable and align the lid and all the various metal slots before starting to replace bolts. Alignment of all the metal slots can be a little awkward, as there's some drift in the various components due to the way the cube's internals are put together. Don't be afraid to gently push things into place in order to get the metal "lid" back on. You should then be able to drop the core back into the external case, reconnect the cables and power the system back on.
Summary
I partitioned the disk into a primary 55GB space for OS X, and a 5GB space for OS 9, then installed OS 9.1 followed by OS X. Interestingly, OS X refused to detect my Airport card if it was installed onto a UFS partition. I could find no way of getting it working, the docklet said no Airport card was present, and the network control-panel only had entries for the internal modem and the Ethernet port. This looks like some kind of weird dependancy on the file system type, and is a bit disturbing. Anyone else out there discovered this problem? I ended up having to repeat the install process using an HFS+ partition type for OS X.
Performance is much improved. Most file-loading times are noticably shorter, not to mention the luxury of having 60GB of disk space. Don't expect the new disk to stop some of the long delays associated with some Mac OS X operation though.... Omniweb still seems to take a while to load, but most finder operations seem significantly faster.
When it comes to noise, I'm happy to say that the IBM 60GXP is respectable. The actual disk seek noise is reduced from the factory supplied disk. The Western Digital device made quite a rumble on my desk, the IBM's seek noise is higher pitched and sounds quieter. The background noise made by the IBM's spindle rotation is perhaps a little louder, but isn't probably that much different to the factory supplied disk. I've noticed a little more warm air rising out of the cube's ventilation slots since adding the new disk, but the difference is marginal. It won't make a difference to the long-term lifetime of the cube's components.
- Matt
Mail me at: