PowerBook G4 Diary: Under the Hood

(WARNING: This diary contains explicit images of a Titanium PowerBook G4 in various stages of disassembly. People who have trouble viewing the graphic violation of a pristine PowerBook should not read this journal. This information is presented for educational purposes only, and is not intended to endorse or otherwise invite the dismemberment of PowerBooks by our readers. Remember, we are professionals. Don't try this at home!

For those who choose to read on, know this: No PowerBook was harmed in the making of this diary. Well, for the most part.)

In a real sense, it's all been leading up to this moment. While the tour has been interesting, what makes the Titanium PowerBook G4 really different is what lies under its skin. As we saw in my last entry, the Titanium PowerBook G4 provides a nice if not monumental jump in performance. Apple could have put a G4 processor in the old G3 chassis and stopped there. Thankfully, this was not Apple's only goal with the Titanium PowerBook G4, nor should it have been.

Because of the limits caused by portability requirements (most notably having to run off of a battery on a regular basis), what you can do to improve a portable system will always lag behind what you can do with a desktop computer. Where a portable really should shine is -- big surprise -- portability. How light it is, how small it is, and how much it can do given its size and weight.

To determine this, no test will really do. You must take it apart.

That's what I spent my weekend doing. What follows is what I found -- the good and the bad -- extensively documented with a lot of photos.

In a way this diary serves double duty: It gives you a vivid peek at what makes the Titanium PowerBook G4 tick. It also serves as a handy guide on upgrading your own Titanium PowerBook G4. Having survived the journey, I can tell you it's a task that could be a whole lot easier to perform.

When I was a kid, I was known for being an incessant tinkerer. No common household appliance was safe when I was around, or at least that's how my mother remembers it.

There's a popular family story about the time I took the TV apart, right down to the tubes. (Yes, TVs used to work with little light-bulb things called vacuum tubes.) My grandfather walked into the living room to find the TV spread across the floor like an Erector set. Seeing this, he announced that I would be in big trouble as soon as my mother came home. To my eight-year-old eyes, my mother was seven feet tall (she has since shrunk down to a much more reasonable 5'6"). The last thing I wanted was for her to be mad. So I set myself to reassembling the TV.

By the time she came home, or so the story goes, the TV was back together and working -- despite a few missing parts.

I guess this goes a long way toward explaining why I've taken apart every Mac portable. I've never felt similarly compelled to disassemble a desktop Mac; there's something about divining a portable "magic." It's like figuring out how the pictures move on that magic box in the family living room.

It was with this story floating in the back of my mind that I lay the patient out on the operating table. It was just like being ten again, about to divine the magic.

I started, naturally enough, by disconnecting all power and peripherals from the Titanium PowerBook G4. I've heard tell that the FireWire bus in particular can sustain a residual charge even when the portable is shut down, unplugged, and without its battery. I'm not sure this is actually true, but why take chances?

Next I turned the unit over to see which tool I'd need to remove the bottom plate, an operation necessary to get ot the AirPort slot (more on this later). Ah, good! A standard Phillips screwdriver would do the trick! Apple has a long history of using the much less common Torx screw to secure its portables; it's good to see the Phillips being used on what is supposed to be a user-accessible part of the computer.

I decided it was best to start at the top, so I flipped the PowerBook over and opened up the clamshell. The Titanium PowerBook G4 uses the same easy-access design as the PowerBook G3. There are two small latches -- one nestled between the escape key and F1 key, the other between the F8 key and the F9 key. Pull them toward you and lift out the keyboard.

Now, there's been much talk about the "fragility" of the keyboard, and it's true, the new keyboard is less a solid piece of plastic than it is like a flexible piece of mylar. However, while the keyboard is floppy when not mounted, it doesn't seem any more susceptible to damage than a rigid keyboard would be. Also, its flexiblity is no doubt required for the magnets to stretch the keyboard into its rigid form when mounted.

In the picture above I've marked some of the magnets and the associated contact points on the bottom of the keyboard.

Be careful not to twist the ribbon cable that connects it to the logic board. While the ribbon itself is not likely to break, the connector and plug could tear off if you're not careful.

Lift the keyboard out without turning it over, and unplug it from the PowerBook before removing it. When you're done, put it where it won't get stepped on.

You can now see the top part of the Titanium PowerBook G4. Now, before you get too excited, I should explain a couple of things. First, the only part of the PowerBook that is user upgradeable from the top is the RAM. The G4 processor is mounted under an elaborate heat sink that you can't remove without pulling out the logic board, which you must do from the underside of the computer. Second, even if you could get under the heat sink, there's nothing there to upgrade -- the CPU is soldered to the logic board.

Before anyone asks, the same is true of the graphics subsystem. As much as I would have liked to see the ATI Radeon Mobility chipset in this machine, the ATI Rage Mobility chipset is what it comes with and all it'll ever have.

While the modem card isn't soldered on and seems tantalizingly close to being removable, it isn't . . . not without removing the logic board from the bottom. When I tried to pull the card, the only thing I managed to do was snap off a board spacer that I was never able to get back in place.

Likewise, you can't remove the DVD drive or even see the hard drive from the top of the portable. You can see the AirPort card, but you can't get to it from here. The PC Card socket sits on top of the AirPort slot.

So about the only thing you can do here is add or replace RAM. It's very easy to do so -- just pull aside the tabs on either side of the RAM board, and then pull up on the board; it pops right out. To install a board, slip it into the slot you've chosen and, once it's seated, press down. It'll snap into place.

There are two slots: on the 256MB models, the bottom slot is filled with one 128MB RAM card.

That's about it for the top. I closed the clamshell and flipped the unit over. Taking my handy Phillips screwdriver, I went to work on the bottom screws. This turned out to be harder than it looked. Whoever installed the AirPort card in my PowerBook put a couple of the screws in at a bad angle and, rather than removing them and trying again, used too much force. I could actually see that the screw heads were mounted slightly off angle.

I worked at it for a while, careful not to strip the heads while still using enough force to get the screws out, and after about half an hour of stop-and-go work, I got all eight screws out. Lifting off the bottom cover was also a challenge. Because the bottom is made of very thin metal, it will bend. In fact, it will bend any time you put undue force on it. And once you bend the case, it'll never go back into proper form. I ended up using the tip of a flat-head screwdriver to pry the cover off.

Turns out that on the Titanium PowerBook, all the action is really on the bottom, not the top. Here's where you get to the hard drive, the AirPort slot, and if you're daft enough to try, the DVD drive.

Adding an AirPort card is almost as easy as adding RAM. First, using your finger, gently lift up on the edge of the slot -- it should come up at an angle. Next, connect the antenna plug into the card. This can be a little tricky, but don't force it.

Once you've got the slot popped up and the wire in place, slide the card into the socket, with the AirPort logo facing the logic board. When you push the card back down, there is a small metal bracket that snaps around the antenna plug.

It's clear that while Apple expects users to install AirPort cards -- the company even goes to the trouble of including a somewhat vague diagram at the bottom of the battery-storage bay -- it doesn't have the same feeling about the hard drive. First, you're going to need a Torx screwdriver to remove the two mounting screws that are hidden on the left inside wall of the battery bay. It took me forever to find these two little screws!

Once you have those two screws out, carefully pull the hard drive out from the right edge. Be careful to save the clear plastic shield for when you put the hard drive back.

Also be sure to save the two little rubber gaskets around the Torx screws. I didn't realize they were there and almost lost mine while removing the drive. You will need them to put the drive back in.

I don't believe there will be any third-party drives that will fit into the PowerBook. The bay is very tight. And even if you could do it, you wouldn't want to. I was surprised how easy it was to remove this drive -- just remove two Torx screws in plain sight, and it lifts right out. Well, almost. You see, the drive is connected to the logic board by a bundle of ribbon wires and tape that looked like such a nightmare to untangle, much less reconnect, I decided not to try. I did, however, lift it up long enough to give you a peek.

Because a number of people on Macworld.com's forums asked for it, here's a picture of the CPU cooling fan. If I hadn't seen it for myself, I wouldn't have believed it was there. It's that quiet.

All that remained for me to do was replace the drive and put the bottom cover back on, and the tour was complete. Easy, right? Nope!

The first thing you need to do to replace the hard drive is wrap that plastic sheath back around it. Whether it's there to protect the drive from shock, electrical surges or cosmic rays, I'm not sure. But I am sure I wasn't going to take a chance on it not fulfilling some critical function in the PowerBook.

Remember those two rubber gaskets? Well, I hope you saved yours, because not only do they secure the hard drive to the PowerBook, they also work as shock absorbers. The only way I could get them to stay in place while I squeezed the hard drive back in place (there are two similar rubber shocks attached to the left side of the hard drive) was to tilt the PowerBook on its side. Managing this while holding the plastic shield on the drive required a level of coordination I hadn't needed since I stopped taking piano lessons.

Then I screwed those two Torx screws back into place.

All that remained now was to put the bottom back on. As I was soon to discover, getting it off was hard, but getting it back on was harder still.

On the leading edge of the PowerBook are a row of snaps that fit in matching grooves on the cover. I figured the best way to put the cover back on would be to slide it into place from the front, ensuring these snaps and grooves met.

But when I took this approach, the back of the cover didn't line up. I decided a better approach would be to start from the back and then snap the front tabs in place. I lined up the back and started on several of the screws; then I snapped the snaps in.

But when I attempted to finish screwing in the screws, a bump appeared in the center of the cover. The more I turned the screws, the more pronounced it became. Rather than chance putting a dent in the bottom of the case -- or worse, popping a hole in it -- I removed the screws to see what was going on. That's when I discovered a hitherto undiscovered snap that necessitated sliding the cover on from the front. Back to Plan A.

After several attempts, I finally got all the parts to match. This was especially tricky around the battery bay, where there are two tabs on the cover that must fit precisely into two small grooves before the cover is firmly in place.

Then I started to put the screws back in, but I discovered that the screws didn't want to go back in, at least not straight. It took several tries with each screw to get them to seat properly. One refused to seat no matter what I did, and would finally refuse to budge about halfway in.

I don't know if this was caused by the misplaced screws I discovered earlier, or if it was a problem with the cover design. I ultimately decided to go without the screw, but I plan to try this again with the Titanium PowerBook G4/400 when it arrives.

Well, that's it. I opened it up, got inside, and put it back together, and the Titanium PowerBook G4 still worked -- as the photo below demonstrates:

Of course, I did not get away totally scot-free. In the extensive handling of the PowerBook, I inadvertently discovered something that several of you asked me to test on purpose: yes, you can scratch a Titanium PowerBook G4, at least the paint on the lid: There, I hope you're all happy now!

And, of course, there were the obligatory leftover parts: one screw and one board separator.

Grandfather would be proud!

Want to discuss the Titanium PowerBook G4 lab results with Andrew Gore? You can do it now, in our Portable Macs Forum.

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