Kernel SOMETIMES appears missing

[nielsenja]

Hi, I've had my iMac (Model Identifier in System Profiler is iMac7,1) for almost 2 years now and had pretty much no problems whatsoever until about a month ago, I've started getting an issue where when I get home from work, I have to attempt to boot/wake my computer up for about 30 minutes before it will finally boot...

At first I would just let it sit at the grey screen for 5-10 minutes until I manually restart it, then it would get to the loading icon spinning for 5-10 minutes, and I would lose patience and manually restart, and this would go on and on until it finally boots.

Then I learned about Command-V to find out more of what's going on. Today, I got the error:

Error loading kernel 'mach_kernel'

Which was pretty frightening. However, restarting a few times like usual, it finally found it and loaded just fine. And now it's working fine.

It feels as though my computer has to take 30-40 minutes to "warm up" before it's able to find my kernel. Has anyone else experienced this? I have no idea what to do but I get a feeling of impending doom, particularly since I am no longer covered by warranty. Is my computer going to stop booting soon?

Please help!

Thanks,

Jon

 

[dmmcintyre3]

Put it to sleep don't shut it down.

Try an reinstall of the Mac OS X.

 

[nielsenja]

Put it to sleep don't shut it down.

Up until a month ago I NEVER shut my Mac down. When I wake my computer up from sleep it loads whatever screen was up previously and is unresponsive. I have left it for hours before and came back and it was still unresponsive.

The result is that I have to reboot my computer any time I wake it up. I misspoke when I said shut down, since I never shut my computer down.

Try an reinstall of the Mac OS X.

Before I do something drastic I would like to try to understand what's going on... it seems to me that it's less about the software and more about the hardware if it's unable to find the kernel *sometimes* but then most of the time is able to find it.

 

[nielsenja]

Nobody else has any thoughts?

 

[Makosuke]

Frankly, based on those symptoms, impending doom isn't an inaccurate feeling to get.

I wouldn't, however, assume that any major component is close to failure. It's drastically more likely that there's either a software problem (in which case doing an archive-and-install reinstall of the MacOS would fix it) or you have a failing hard drive. It could be something else, of course, but that's what I'd look at first, particularly since it seems time-based--that does sound more like a hardware component (unless it's just coincidence, or it's always on the 5th time and just seems like X minutes, or something).

First, make sure you have a current backup of anything important on the machine. You should anyway, but now would be a very good time to correct the mistake if you don't, and avert potential disaster.

Second, run through the "reset PRAM" procedure; a quick search will turn up detailed instructions, but hold down command-option-P-R when you first power the computer up and keep holding through 3 startup chimes.

Third, boot from the OS install disc and run Disk Utility from the menu. Select your hard drive and look down at the bottom where it says SMART status. If it doesn't say "Verified", you've got a failing hard drive and you're going to need to replace it. Consider yourself lucky it didn't die more abruptly.

If it's ok, run "Repair Disk". If it finds anything wrong, run it again until it stops finding anything.

While you've got the install discs out, find the disc that came with the computer that has "Apple Hardware Test" on it. Stick it in and do whatever the disc says to boot into the hardware test (usually hold down D or something like that). Run a test and see if it finds anything--if so, there's your problem. With luck it's just the hard drive or RAM. If not...

Try it for a while and see if the above has gotten it back into working order. If not, look up the procedure for "Archive and install" to reinstall the OS. That will pretty much eliminate any software cause.

If none of the above fix it, could still definitely be a dying hard drive, or if you're unlucky something more serious.