Interpreting Kernel Panic Log

Question

I have a 15" aluminum G4 that's about 2.5 years old. I'm running OS 10.4.7. I've always had problems with kernel panics but I've learned to live with them -- until recently. They seem to be increasing in frequency; about 4 per day now. It usually happens when I'm online, which I often access via airport, though I'm plugged into a LAN at work. I use Firefox as a browser. I would appreciate any insight into the meaning of the following report from my computer's panic log and, I'm hoping, solutions to the problem. The log seems to show the same message consistently.
Thu Aug 3 23:02:04 2006
panic(cpu 0 caller 0x000A8E00): Uncorrectable machine check: pc = 00000000006B452C, msr = 0000000000149030, dsisr = 42000000, dar = 00000000E0F48000
AsyncSrc = 0000000000000000, CoreFIR = 0000000000000000
L2FIR = 0000000000000000, BusFir = 00000000fff00000
Latest stack backtrace for cpu 0:
Backtrace:
0x00095718 0x00095C30 0x0002683C 0x000A8E00 0x000A8090 0x000ABD80
Proceeding back via exception chain:
Exception state (sv=0x3C3D1A00)
PC=0x006B452C; MSR=0x00149030; DAR=0xE0F48000; DSISR=0x42000000; LR=0x006C9060; R1=0x17553D30; XCP=0x00000008 (0x200 - Machine check)
Backtrace:
0x038FAC60 0x006C9060 0x002D0D00 0x002CFBC8 0x000A9914
Kernel loadable modules in backtrace (with dependencies):
com.apple.iokit.AppleAirPort2(404.2)@0x68a000
dependency: com.apple.iokit.IONetworkingFamily(1.5.0)@0x5eb000
dependency: com.apple.iokit.IOPCIFamily(1.7)@0x480000
Exception state (sv=0x32B64780)
PC=0x00000000; MSR=0x0000D030; DAR=0x00000000; DSISR=0x00000000; LR=0x00000000; R1=0x00000000; XCP=0x00000000 (Unknown)
Kernel version:
Darwin Kernel Version 8.7.0: Fri May 26 15:20:53 PDT 2006; root:xnu-792.6.76.obj~1/RELEASE_PPC
Thanks for your help in advance. - Rick

Answer 1

Hi, Huskies81.
The panic log is flagging your AirPort card:
Kernel loadable modules in backtrace (with dependencies):
com.apple.iokit.AppleAirPort2...
Be sure the AirPort card is installed properly and hasn't come loose.
If that doesn't solve it, see my "Resolving Kernel Panics" FAQ. This FAQ includes step-by-step instructions for identifying and resolving some of the most common causes of kernel panics.
My FAQ is a roadmap: start at the beginning and work through to the end, including the "If all else fails..." section if a cause or resolution is not found in an earlier troubleshooting step therein.
The "uncorrectable machine check" panic, i.e.
panic(cpu 0 caller 0x000A8E00): Uncorrectable machine check...
indicates a RAM problem, low-level programming error, or other hardware issue such as a defective processor or logic board problem. A faulty or improperly installed AirPort Card would qualify as "other hardware issue." However, even though the backtrace sections of the panic logs are flagging AirPort components, there may be other issues causing the panic and the AirPort components were merely engaged at the time of the panic. Hence why it is important to follow the troubleshooting roadmap in my FAQ.
Good luck!
Dr. Smoke
Author: Troubleshooting Mac® OS X
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