2006 iMac keeps giving kernel panics!

[Diogones]

Hey all,

I have a 2006 2.16 C2D iMac running 10.7.5, and I experienced a kernel panic late last night. I was listening to music, browsing the net, and had a few programs open. I was suddenly assaulted with the kernel panic screen, and after a few seconds the Mac shut off.

I waited a few seconds, and then turned the Mac back on. I ran into the grey prohibitory sign, so I rebooted the Mac and attempted to use Safe Mode, but the Mac shut down while I held the Shift key.

I restarted again, this time selecting the Recovery HD partition, which successfully started up. I ran Disk Utility, which reported no errors, but I wasn't convinced. I also ran fsck -f in Terminal, but it didn't report anything strange either.

I shut down the Mac again and this time booted from a DiskWarrior USB stick I had created for just such emergencies. It scanned the drive, and found a few damaged files, which I repaired by rebuilding the file directory.

I rebooted again as usual, crossed my fingers, and lo and behold I am back in business!

I didn't waste any time after that. After ensuring I had my Time Machine backed up with the latest changes to my system, I ran TechTool Pro on my Mac, and found that the Hardware ECC Recovered range looked questionable, but I'm not sure if i should worry about it.

I did find the kernel panic log, which was just a crashed application log.

The iMac gave me two more kernel panics after that, both on the same day. This time, they both left actual kernel panic logs in the Logs directory.

I've attached a copy of the readout from the first application crash log from the first panic, and the two kernel panic logs in the Console.app. I've also enclosed a snapshot of the TechTool Pro test result of the hard drive in the Mac.

If someone here would be gracious enough to help me decode these logs and find out what is happening with my Mac, I would be much obliged! Based on the TechTool Pro report, I suspect the hard drive, but that might not be it.

 

[Kaveman]

Very comprehensive post, great!

Sorry, can't do much about Kernel Panics, normally I would recommend taking it to an Apple Service Center near you, but you sound like someone who could easily try the next fix.

Boot from recovery and do an Install in Place. This should just reinstall your System leaving your User space untouched.

 

[Diogones]

Thank you for your reply and kind words, Kaveman! I tried to include as much detail as I could without getting too wordy.

Well no new crashes today, and I did run a permissions repair, which found an incredibly long list of incorrect entries, and corrected them. I ran it twice just to be sure.

I did a Google search on the application crash report, and it turns out that the app that crashed is XpcHelper. According to this helpful page from MacInsider:

xpchelper is the XPC helper agent. XPC stands for "X Performance Characterization", a graphics benchmark that tests X Window performance.

xpchelper performs services on behalf of the XPC IPC facility, where IPC stands for "Inter Process Communication" which refers to different programs or processes communicating with each other, usually requesting information (for example, a program requesting information from a database).

Not sure if that has something to do with this kernel panic issue, but it might since the crash log from the first kernel panic mentioned it.

I'll keep investigating, and report any new crashes. Hopefully the two permissions repairs might have solved it, but I'm not hedging any bets yet.

Thanks for the Repair Install suggestion; I may do that if the crashes continue. If they persist after that, at least I can rule out a faulty OS X installation, and examine the hardware (especially the hard drive) more closely for any signs of failure.

 

[Diogones]

(SOLVED!) Re: 2006 iMac keeps giving kernel panics!

Well there were not any new crashes, and I think I might have found the solution to this problem. After checking around with a few other forums, a helper poster read my kernel panic logs and suggested that I uninstall the third-party kexts, and see if that fixed the problem.

It turned out that there was a kext leftover from a program I had deleted. VirtualBox had four kexts leftover, even though I had dragged the icon to the trash and deleted it. Thankfully, I found a helpful script from kuneri.com that instructs the Mac to remove everything related to VB.

After running that command in Terminal, I haven't had a crash since. However, just to be on the safe side, I also cloned my existing setup, and made sure my Time Machine backup was up to date.

It's possible the HDD in the Mac could be failing, but I don't see any evidence from the tests I've run so far. It really seems like I managed to fix this recurring error. However, with my backups, if the drive should fail I'll be prepared, and I won't have lost anything.

I'm marking this thread as solved. Hopefully my solutions will help others who also are suffering from kernel panics.