Freezing G5 Quad: It’s really dead now

Posted by Pierre Igot in: Macintosh
October 9th, 2006 • 2:57 pm

This is yet another installment in the on-going saga of my freezing Power Mac G5 Quad computer.

I am afraid that I have to report that the machine has completely “died” again. And this time it seems to be for real.

I cannot boot either from the internal hard drive or from the system CD that came with the machine. When I turn the machine on, the red LED behind the power button glows for a second (which is normal) and goes off, the fans start turning, and then after a second or two, even before the startup chime, the red LED comes back on. I can then hear the startup chime, and the machine does start booting (either from the hard drive or the CD), but the booting process stalls after a while.

Regular Betalogue readers might remember that my G5 Quad has already had a similar episode where it wouldn’t boot either, with that same red LED coming on behind the power button. It was back in September. At the time, I thought that the machine was dead, but then a Betalogue reader suggested opening up the machine and making sure that everything was in place. Back in September, after reading his suggestions, I did just that, fiddled with a few connections (there aren’t many of them), closed the machine, and it came back to life.

This time, however, no amount of fiddling with things can bring the machine back to life.

Remember that, because of the on-going problems with the G5 Quad freezing or experiencing kernel panics, I got the machine’s logic board replaced by an Apple-authorized repair shop on September 29. The repair did not fix the problem.

I got home on September 30, plugged the machine back in, and followed the repair shop’s instructions to do the “thermal calibration” of the CPU, using the special CD that the repair shop had given me. That went fine. But when I then started up the computer and tried to use it, I got a couple of kernel panics within a few hours, and then another one later on at night.

Then for a few days I didn’t get any kernel panics at all. Then on Wednesday, the machine started freezing again. I got a freeze or a kernel panic once a day on average for a few days, and then on Saturday things started going downhill again. I got several kernel panics in quick succession (within a few hours), and then the complete failure occurred, with the red LED coming on before the startup chime and staying on, and the machine failing to boot.

Remembering what had happened in September, I tried opening the machine and fiddling with things. That didn’t revive the machine. Then I tried shuffling the RAM modules, putting them in different slots, just to see if that would make any difference.

Much to my surprise, it did. The machine started working again, with the red LED no longer coming on. I decided to try and boot the G5 from the service CD that the repair shop had given me, since they had told me it was a CD with a more detailed battery of tests than the standard hardware testing CD that comes with the machine. (These days, the hardware testing CD is on the system CD itself. You just have to boot your machine with the CD in and the Option key down, and then the machine lets you choose which volume you want to boot from, and the hardware CD is one of the options, along with your startup volume on your hard drive and the system volume on the CD itself.)

That service CD does indeed come with many more options for testing. You can test all kinds of components in the machine, from individual sensors to fans, etc. I tried testing everything except the RAM (because I knew it would take a long time) and the CPUs. The G5 passed the tests with flying colours.

But then when I tried using the machine again for work, I got another freeze (or kernel panic, I can’t remember) within a couple of hours. This time, I opened the machine, removed the 4×1 GB of third-party RAM, put back the 2×256 MB of RAM that came with the machine, and booted from the service CD. I used the CD to test both the RAM and the CPUs, and both passed the test with flying colours. In other words, with only the 2×256 MB of RAM, all components of the G5 passed all the tests.

So I decided I would try to use the G5 Quad with only the 2×256 MB of RAM for a while. Regular Betalogue readers remember that I had tried this in the past, and had had a pretty awful experience with a very sluggish machine, until I turned off some system utilities. Even without these utilities, the machine was still is rather slow with only 512 MB of RAM, so I hadn’t used it for more than a few days with only 512 MB of RAM, and had not experienced a single freeze or kernel panic during that time. In other words, I had not ruled out the third-party RAM as the culprit with absolute certainty.

But I thought that I should be able to endure a relatively slow G5 Quad for a few days, at least until my new Mac Pro arrives. (It has shipped and should be here within a week.) So I decided to tough it out this time and really try and wait long enough to reproduce the freezes or kernel panics with only the 512 MB of RAM, which was something that I had not done until then.

At that point, I was really convinced that the problem was with the third-party RAM after all—even though the RAM had passed the memtest tests with flying colours and I had tried using my G5 Quad with six different combinations of 2×1 GB RAM modules, which meant that, if the RAM was indeed the culprit, then at least 3 of the 4 modules had somehow become defective.

I was in the process of writing an e-mail to the store that I had bought the third-party RAM from, inquiring about RAM warranty policies and how to go about getting the RAM replaced, when—bam, the machine froze on me.

This ruled out the third-party RAM as the culprit. The machine was indeed also freezing with only the original 512 MB of RAM that came with it.

But then I tried to boot the machine again, and the machine got stuck again. I looked at the front panel, and, sure enough, the red LED was on. Uh oh. I was once again unable to boot either from the hard drive or from the system CD, just like in September.

I was, however, able to boot from the service CD that the repair shop had given me. While in there, I tried running the RAM test and the CPU test again. The RAM test went just fine, but the machine froze completely during the CPU test. The CPU test didn’t get a chance to fail: The testing process itself caused a freeze.

At that point I decided that I would try fiddling with the machine some more later, but that I should first transfer all my files to my older G4 MDD and revert to that machine as my main machine. I was able to use the G5 Quad in FireWire Target Disk mode, even with the red LED constantly on, and I was able to transfer all my files to the G4 MDD that way.

Once that was done, I moved the G5 Quad from under the desk and set it up in another corner of the office with the 30″ display (which I cannot use with the G4 MDD, which does not support such a big display). I tried fiddling with things some more. I tried putting some other RAM modules back in, switching them around, putting them in slots other than the first two, etc. Nothing worked. I tried disconnecting the internal hard drives altogether, and booting from the system CD. That didn’t work either. The machine was well and truly dead this time.

In a way, it is probably a good thing—although I really wish the G5 Quad had waited until the arrival of my new Mac Pro to do this, which would have saved me a temporary switch back to the G4 MDD. It’s a good thing because this time I have a real failure that I can show to the repair shop.

There is little doubt in my mind at this point that the freezes/kernel panics and this complete failure are part of the same problem. And the tests with the service CD seem to indicate that the problem is with the CPU unit itself—which, by the way, the repair shop would also have replaced last week, had Apple not sent a replacement CPU unit that the repair guys couldn’t get to work with my machine.

I cannot be sure, but I strongly suspect that replacing the CPU unit itself will fix the problem. I certainly hope it will, because if it does not, then we’ll be in big trouble. Obviously if replacing the CPU unit does not fix the problem with the red LED, then the repair guys will have to find another solution. However, if replacing the CPU unit does somehow eliminate the red LED, but I still get freezes or kernel panics on a regular basis when actually using the machine, then I really will not know what to do.

By then I obviously will have a Mac Pro as my main work machine, but this G5 Quad is still worth quite a bit of money (I only bought it brand new last November) and it is under warranty. It has to be either fixed properly or replaced. That’s all there is to it. My plan is to use the G5 Quad as a second machine (primarily for design work with Adobe products that are not yet Intel-native, and also for testing purposes, as a file server, etc.), and to get rid of the G4 MDD. But I will only be able to get rid of the G4 MDD once I am sure that the G5 Quad has been fixed for good.

I am starting to think that I have wasted a lot of time dealing with this G5 Quad machine. I certainly hope that, somehow, this current failure will bring about the final resolution that I have been looking for for the past three months.


One Response to “Freezing G5 Quad: It’s really dead now”

  1. A great review on the New Mac Pro at Technological Winter says:

    [...] The one good thing to come out of my on-going troubles with my G5 Quad is that my employer recently agreed to buy me a new machine to replace my … in the way at all.) The machine was ordered from Apple Canada Education on September 29. It was shipped … ’t help that the machine was stuck at the Canadian border during the October 7-9 week-end, which….. [...]

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