10 Replies Latest reply: Mar 20, 2007 7:44 AM by omegaman41658
Kris Jones Level 1 (55 points)
I had a kernel panic this afternoon while listening to a podcast. The panic log reads as follows:

Thu Mar 15 18:17:47 2007
panic(cpu 0 caller 0x000A8A00): Uncorrectable machine check: pc = 0000000000882B50, msr = 000000004000B030, dsisr = 42000000, dar = 000000001C48E3DC
AsyncSrc = 0000000000000000, CoreFIR = 0000000000000000
L2FIR = 0000000000000000, BusFir = 0000000000000000

Latest stack backtrace for cpu 0:
0x000952D8 0x000957F0 0x00026898 0x000A8A00 0x000A7C90 0x000AB980
Proceeding back via exception chain:
Exception state (sv=0x276A6000)
PC=0x00882B50; MSR=0x4000B030; DAR=0x1C48E3DC; DSISR=0x42000000; LR=0x00882B78; R1=0x12373990; XCP=0x00000008 (0x200 - Machine check)
0x00882CC0 0x00863CDC 0x002E94C0 0x002EB38C 0x0008C06C 0x0002921C
0x000233F8 0x000ABCAC 0x01D0BA00
Kernel loadable modules in backtrace (with dependencies):
dependency: com.apple.iokit.IOPCIFamily(1.7)@0x464000
dependency: com.apple.iokit.IOGraphicsFamily(1.4.1)@0x655000
dependency: com.apple.iokit.IONDRVSupport(1.4.1)@0x679000
dependency: com.apple.NVDAResman(4.1.8)@0x68f000
Exception state (sv=0x2736C000)
PC=0x9000B4C8; MSR=0x0000F030; DAR=0x1C48E3DC; DSISR=0x42000000; LR=0x9000B41C; R1=0xBFFFE900; XCP=0x00000030 (0xC00 - System call)

Kernel version:
Darwin Kernel Version 8.9.0: Thu Feb 22 20:54:07 PST 2007; root:xnu-792.17.14~1/RELEASE_PPC


The log would appear to point to a graphics card problem. Has anyone any ideas what might be wrong? Any help gratefully received.

iMac G4 1ghz USB2, Mac OS X (10.4.9)
  • cornelius Level 6 (17,825 points)

    Here are a couple of links you should find helpful:

    What’s a kernel panic.
    Resolving Kernel Panics

    Please do not hesistate to post back should you have further questions or comments.

  • Allan Sampson Level 10 (123,405 points)
    Hello Kris.

    How did you install the 10.4.9 update - via Software Update or by downloading the 10.4.9 Combo or Delta Update?

    I used Software Update and everything was working A-OK for several hours after installing the update. I was updating some backups saved to an external firewire drive and I experienced my first kernel panic since 10.1. or maybe 10.2 - it has been so long now I don't recall which.

    Long story short, if you also used Software Update to install the 10.4.9 update, I did the following and I haven't experienced the same or any problems since.

    Check your boot volume for any directory errors with Disk First Aid repair via Disk Utility when booted from your Tiger install disc.

    If any problems are reported and successfully repaired, run repair again until no problems are reported.

    Download the 10.4.9 Combo Update (PPC?) for your Mac and re-install 10.4.9.
  • Kris Jones Level 1 (55 points)
    Hi Allan, thanks for your reply. I downloaded the Combo Updater and installed that. Following installation I repaired permissions. Other than a small problem with iTunes, which I resolved, everything was fine till the kernel panic today. Since the kernel panic I've used Disk First Aid, which reported everything is fine with the volume. However, I did have to repair permissions, which is not exactly unexpected after a crash.

    If I get a further crash then I may reapply the Combo Update. However, what worries me in the crash report is that it seems to be pointing to a conflict with the graphics card, which is not something I can resolve myself.
  • Kris Jones Level 1 (55 points)
    Thanks for your response Cornelius. I'm familiar with both the threads you linked to. Like many others here, I'm no expert at reading panic logs, but mine does seem to point to a conflict with the graphics card and I'm not sure I can resolve that. However, any advice is most welcome.
  • Allan Sampson Level 10 (123,405 points)
    You're welcome.

    You used Disk First Aid via Disk Utility when booted from your Tiger install disc to run Repair Disk or did you use Verify Disk with Disk Utility from your boot volume?

    If no problems were found, good but FYI, using Verify Disk with Disk Utility from your boot volume can report a problem when no problems are reported and repaired when using DFA via Disk Utility when booted from the Tiger install disc so I can only assume the opposite is also possible so it is always best to boot from the Tiger install disc and run Repair Disk since Verify Disk is part of the Repair Disk process. It is also recommended to do this immediately prior to installing a major OS update such as 10.4.9. This is always more important and a priority over repairing disk permissions.

    You may want to consider using the Hardware Test included with the install package that shipped with this Mac when new and run the Extended Tests when doing so.
  • Kris Jones Level 1 (55 points)
    Thanks Allan. I'd run Onyx just the day before the software update, which verifies the disk and checks its SMART status. I also have Tech Tool Pro installed, which monitors my system regularly. I was therefore confident that there was no corruption on my disk before the installation.

    I haven't had a repeat of the earlier kernel panic, but if I do I will run more extensive tests. I haven't had experience of verify disk working differently from the Install disk, but of course, if the problem recurs I shall try that.

    I know that many advise repairing permissions before an install, but I have sincere doubts as to the veracity of that advice. If one is going to check permissions after an installation, I fail to see what benefit there is to doing so beforehand. If anyone can give me a cogent explanation as to why doing so beforehand is beneficial I'd be grateful.
  • cornelius Level 6 (17,825 points)

    You are welcome. I am not expert at reading crash logs, either. Your kernel panic may well be related to the graphics card and running the Apple Hardware Test may isolate it, but that is not guaranteed. You could run AHT in loop mode, as it may have to run the test continuously for hours if there is an intermittent issue. TTP's hardware test does not, necessarily, isolate hardware issues, either.

    In terms of Repair Disk Permissions before and after installation, I can't say that I understand the rationale of why it is necessary or helpful before, or after, for that matter. However, even though I have Macaroni running and repairing permissions, I do repair disk permissions before and after a major installations. Sympathetic magic, maybe, but, so far, it has worked.

    The fact that the kp has not recurred may indicate that the hardware problem is intermittent, if, indeed, it is a hardware problem. On the other hand, you have done quite a bit of system and directory repairs, and, if it were a software issue, it may have been resolved in that way.

    Should the issue recur, please do post back.

    Good luck.

  • David Gimeno Gost Level 7 (20,775 points)
    > If anyone can give me a cogent explanation as to why doing so
    beforehand is beneficial I'd be grateful.

    You’ll find no such explanation, simply because those recommendations have no technical basis. Permissions have no bearing on the ability of the installer to do its job because it runs with administrative privileges anyway. At best, you’ll see it argued that permissions can fix a variety of problems, which is true in some cases but clearly irrelevant as to why it may be necessary or useful to do it before installing a system update.

    Actually, Apple doesn’t mention anywhere the need to repair permissions either before or after installing a system update, not even for troubleshooting system update issues -- see Troubleshooting installation and software updates.

    Repairing permissions is harmless, though, so I’d have nothing against such recommendations if it wasn’t because they are usually made in a way that gives users the impression that some kind of magic ritual is necessary when installing system updates and makes it much harder to understand what’s going on and what the real cause of the problems could be.
  • Kris Jones Level 1 (55 points)
    Thanks David. I've never seen the point of repairing before an install, but can see the benefit of verifying and repairing afterwards. In fact my system showed permissions errors both after the 10.4.9 update, and the iTunes 7.1.1 update.

    I haven't had another kernel panic so I'm content for the time being and will mark my question as resolved.
  • omegaman41658 Level 1 (5 points)
    How does one find the panic log? My 10.4.9 update was the first ever KP I had on my new iMac 20 Core/Duo. I was very disspointed in that. I have always prided my self on a well running box. I run Onyx or Applejack almost twice per week and was not really too happy. I reinstalled the update and all has been well so far. But I did find all of my Safari preferences to be gone except the cookies. I had to reset my Saft and Stand for Safari, wasn't keen on that either.