IBook G4 freezing, and nothing much more

Question

I’m hoping for some creative help with a very troubling problem I’m having with my G4 iBook.
Bought in 2004, this 14-inch iBook is running Tiger (though it came with Panther) and has 768 MB of RAM, a 60 gig hard drive, and a 1.07 GHz processor. It has never caused me any problems and I have been able to run an impressive array of programs at the same time with only about a dozen full-scale crashes that I can recall.
About three weeks ago, the computer started to freeze repeatedly, particularly when hooked up to an external monitor or TV. I ran the Disk Utility, both from the computer and off the Mac Os install disk, though no problems were found. The freezing continued and became even more persistent. At that time, programs would become non-responsive, the clock would stop, but the mouse pointer could still be moved. Sometimes, a thin line of zebra stripes would appear at the top of the screen and the mouse pointer would not move. A small, multi-coloured line (about one pixel wide and barely the height of the top menu bar) developed on the screen and has remained since.
Luckily, I use the computer for work and sent it off to our company repairperson, who specializes in Macs. As always seems to be the way, he could find nothing wrong with the computer — it worked fine for him over the three days he tested it. He installed a fresh copy of Tiger, removed Norton Utilities, which often can often cause operating problems, according to him. (He did not remove any other programs.) He did a hardware diagnosis and found no problems. He sent it back to me.
When I got the computer back, at first it worked fine. The only problem was that a blue screen would appear and the computer would become unresponsive when I hooked it up on the fly to an external monitor. (The computer tech suggested I hook up the source before powering the computer on to avoid a crash, though this was unnecessary before).
I moved my preferences from the archived system folder to the new library folder. The freezing then returned. This time, much worse. Without going into detail at this point about the freezing, I can say that the freezing became so bad that I decided to do something drastic — wipe the hard drive and re-install Tiger completely, which I did. (I backed up all my documents and preferences on another hard drive, of course.) This seemed like a good thing to do, seeing as the problem may have been with one or more of my programs. I was getting some corrupted file messages before I wiped the hard drive.
Sadly, even after two reinstalls of Tiger, freezes are persistent. I have also reset the power management unit several times, along with resetting the Parameter RAM. I have also turned off hard disk spin down and the option that puts the computer to sleep (in the Energy Saver control panel) to avoid unnecessary sleeping. No luck — freezes continue.
At this point, the computer has a clean hard drive and fresh copy of Tiger, including all the software updates through the Apple menu. I do have a few basic programs installed, such as Microsoft Office, iPhoto and some small, free downloadable programs. There is about 41 gigs of free hard disk space.
Here are the freeze patterns:
- When the computer freezes, the seconds counter on the clock stops, all programs are unresponsive and no force quitting is possible. The pointer can still be moved by the mouse, but that is the only action the computer makes. The only way to reset the computer is to hold down the power button.
- Typically, if the computer is powered back on within less than five minutes, it boots up past the Apple symbol and spinning dial, then freezes on the blue screen.
- If I wait for about five minutes or more, the computer will almost always boot up normally.
- The computer seems particularly susceptible when peripheral devices are attached while running. For instance, it has crashed a few times while the computer was running as soon as — or shortly after — I inserted a USB key, a firewire cable (for a firewire transfer), or unplugged and re-plugged in the power adapter.
- It has also taken to freezing or crashing when audio or video is played — iTunes, DVD Player (especially) or Quicktime. It doesn’t always freeze or crash, but it more often does than does not. It has crashed a few times when Acquisition — a peer-to-peer file sharing program — was running. I am currently running the Internet through an Airport wireless connection.
- The computer was freezing consistently today after about 45 minutes operation, even with no programs running. I reset the Power Management Unit, Parameter RAM and disabled sleep and hard disk spin down, and it ran for two hours this evening (with no programs running and no network connected) and did not freeze. I intend to try a longer run overnight to see how it fairs.
Sorry for the long description. I just want to be very thorough with my explanation so potential problem solvers have enough to go on.
Hope you can help! I really appreciate it. I love this computer and am not quite ready (financially) to buy a new one.
- niall

Answer 1

Luckily, I use the computer for work and sent it off to our company repairperson, who specializes in Macs. As always seems to be the way, he could find nothing wrong with the computer — it worked fine for him over the three days he tested it. He installed a fresh copy of Tiger, removed Norton Utilities, which often can often cause operating problems, according to him. (He did not remove any other programs.) He did a hardware diagnosis and found no problems. He sent it back to me.
This is the major sign of hope so far.
If the computer could run for 3 days and be functional enough to reinstall the OS, the logic board and HD can't be totally FUBAR.
Can your computer guy lend you a different power adapter?
Now, I'm guessing the computer guy didn't plug in peripherals while he was testing, so the problem may be with your ports. There could be a cracked solder joint, or the hot-plugging of your TV connection could have traumatized some electrical component inside the iBook.
You can't count on your OS at this point, because you have done some forced shutdowns. I'd recommend borrowing a new power adapter and seeing if Ubuntu can run your iBook for an extended period without freezing. Probably best not to go heavy on the multimedia test, since that could just as well be an Ubuntu bug.
Running Ubuntu with it's screen saver going for a day will be a pretty good test. Since Ubuntu loads into RAM, your system will get a thorough workout. Don't plug anything else in. I'm trying to reproduce the results that your computer guy got.
There's one other far-fetched possibility that would be good to check: could some of the outlets in your house be improperly wired? You can pick up an inexpensive outlet tester that will check to make sure the hot and neutral wires aren't reversed, and that the ground (earth) is properly grounded. You should check the proper wiring of all outlets that are involved with the computer, namely the TV's outlet, the monitor's outlet, and outlets that power any peripheral.
Again, this is a long shot, but it has been the answer for me in the past.