iMac (late-06 CD) Won't Boot 10.6.8 - Blue screen w/ wheel

[computiNATEor]

Hey guys,

Long time user of the forums, but first time writer! I'm having an issue with my grandmother's 17-inch iMac (mid-2006 CD, iMac4,2, Education special at only $899) running OS X 10.6.8. Resolution set to 1 step below the native 1440x900 to help with her old eyes.

Here's the issue:

I have an application, TeamViewer, that has been causing problems with Parental Controls (which we use to keep granny from messing up too much of the system, and getting too lost). TeamViewer has been trying to auto-update, and with each update, auto-updates are re-enabled. -_-

Upon a prompt asking for admin privileges, the computer froze after I had typed the admin info and pressed the "authorize" (or similarly phrased) button via the return key. The mouse and keyboard no longer responded, and the system was unresponsive to power button "taps." After trying to access the force-quit dialogue, nothing appeared, and I hard-shut down the system after holding down the power button for ~7 seconds.

Upon the following reboot, the iMac went through the normal grey-screen-with-spinning-wheel process, followed by a blue screen. The blue screen then showed up with a spinning wheel, which I haven't seen since OS X 10.4 shutdowns, and raised alarm bells for me. It then cycled back to a blue screen of a slightly different hue; probably a different ColorSync profile. Back to the spinning wheel. Repeat ad infinitum.

Tried a simple command-option-R-P NV/P RAM reset. No difference, though the resolution set for grandma's aging eyes was reset to the default.
SMC reset. No dice.
Single user boot. fsck -fy - fixed some errors; still won't boot.
mount -uw / proceses just fine, but I'm unsure what else to do. Typing "exit" to launch Aqua/GUI results in the blue screen exchanged with the black Single-user screen, with a white cursor for text. Typing on the keyboard does input text, though it doesn't seem to have an effect.

I guess I'm asking, what's my next step? Boot from an external volume to verify the iMac's hardware? If the hardware checks out OK, what hard drive testing tools do you guys recommend?

I carry around an old boot on my MacBook Pro (mid-09 2.66) for gaming; should I use a FW800 cable to test next?

Thanks!

Nate

 

[keysofanxiety]

Hi Nate, definitely best to boot from an external volume to verify the iMac's hardware. Hope this doesn't sound patronising if you already know the below.

If you've got Mavericks upwards on your diagnostics volume, download SMART Utility to verify HDD SMART data. Only takes a few seconds to check. If you're running Mountain Lion or earlier on your diagnostics volume, here's an earlier version of SMART Utility that'll work. Of course if it is the HDD, that'll need to be replaced ASAP as any volume repairs will just be like putting a plaster on a shark bite wound.

If it's not the HDD and it won't repair through Disk Utility in your diagnostics HDD, you can always try to run DiskWarrior as that's a heck of an application. Might do the trick.

If that's clean, could possibly be the RAM, that's worth checking. If you can get MemTest on a pendrive, try boot into that with the Alt key on startup (still works fine on Macs as well on Windows), and run that.

In all honesty with the age of the machine and wear that happens over time on spinners/platters, it's likely to be the HDD. If it isn't that and the RAM's good, I'd just back up the data through your diagnostic volume and then wipe/reinstall the OS with a fresh copy of Snow Leopard.

 

[computiNATEor]

In all honesty with the age of the machine and wear that happens over time on spinners/platters, it's likely to be the HDD.

That's my thought, too. Thanks for the links! I carry around a boot of 10.6.8, and my day-to-day El Capitan boot for everything else, so I'll be trying that this weekend. I'll report back with what I get...