Crashing iMac (Black screen or spinning beach ball)

Same problem here with my iMac. Anyone figured this out yet? This is really annoying!

Graham, what you've written is complete deja vu of what I've experienced with a mid-2008 24" iMac.

Like you, I'm putting it down to something beyond "coincidence" that the moment I had installed 10.6.3, things started going gradually haywire on this particular iMac.

My need to install Snow Leopard was so that we could run the Adobe CS4 suite of software which had SL as a minimum requirement; had we not needed to run CS4, I'm confident the iMac would've still be running fine today.

Initially thinking that it was a corruption in the OS, I decided to re-install the system. This did nothing to fix the problem. My attention then turned to the hard drive, thinking that there may be a few bad sectors. I ran DiskWarrior on it, did all the Cocktail scripts, Tech Tool Pro, Disk Utility, anything I could find. Everything said the drive was in order, the S.M.A.R.T. status was cool, etc. All these tests were run, where possible no less, when the iMac wasn't behaving erratically. Furthermore, I did verbose boots and read the text. I even downgraded to 10.6. Still nothing. It's like the damage had already been done, maybe by any possible and irreversable firmware upgrades which ran during the 10.6.3 upgrade?

One day I was dusting the top of the iMac and noticed the God-almighty heat on top of the aluminium bezel, moreso, the top left-hand side. I then read reports about over-heating so I installed smcFanControl on a whim. The moment I did that, I got my iMac back! Despite the increased noise of air being rushed through the cavity of the iMac, it is now a useable computer. I made it a login item so that it starts up when it hits the Finder to reduce the chance of it heating up and being unuseable again if it sits idle for too long.

My conclusion is that when they were creating 10.6.3, Apple either removed or screwed up something to do with Processes and/or CPU usage. Or even temperature management. The only way of overcoming this is by manually overriding the normally system-controlled fans and using smcFanControl as a patch-fix until Apple addresses this problem (unlikely) or, your next iMac (most likely) 🙂

Hope this helps a few people out there!

Did the 6.5 version work? I'm consigning downgrading as well but wanted to make sure first. Has anyone had any success with upgrading to lion?

Thanks for this tip, Dave. After being stuck with a beachball iMac (early 2008 24", 3.06 ghz 4gb, Core2Duo) for weeks and trying to come to terms with the only remaining solution, total reset and wipe, I read your post and checked the temperature of the top left-hand side of the Mac. Smoking hot.

Installed SMCfancontrol and yes: I got my Mac back too! Albeit a bit noisier since the fans are working harder, but at least it's usable.

When I consider the crash pattern I experienced before it makes sense that it's a temperature issue I'm having. The iMac would work fine right after being turned on. I could even watch a full movie (when no interface actions are performed), but after being turned on for a while it would be beachballing whenever I tried to perform an action. Probably because of overheating.

My problems only started December 2011 long after I started running Lion OS, so I really can't pinpoint the reason for this sudden behaviour. Just happy that SMC has provided me with a solution.

I started having the same problems several months ago: total freeze ups (usually except for cursor) coming out of sleep, as well as occasionally at random; rarely, a grey black screen (but you can hear that the machine is on), once or twice freeze ups with the spinning beachj ball.

I am running 10.6.8.on a late 2007 core intel MAC. I had very few to no problems with 10.6.6, more with 10.6.7 and many more now with 10.6.8. If you read various threads, you will note that there are many of people having these same "freezeup/crash" problems. There are very many with the problem who have gone to LION--one extant thread is over 105 pages long, and you can find it here! In fact, some LION folks are trying to go back to Snoiw Leopard where things weren't so bad in this regard, but are finding that it is difficult to make that transition.

SO FAR, NO ONE HAS COME UP WITH A CERTAIN CAUSE OR CURE!!!

Also, I have gone the route--as have MANY folks-- of going to Apple with machines and being told that there are no hardware problems after the hardware tests they do as well as doing the other few things that are suggested.

I am here trolling for answers, as I often do, but there are none so far, and it is frustrating after three years of no problems like this in my case. This 'freeze/crash coming out of sleep' thing etc., has really come into prominence in about the last 1/2 year.

I suggest that you all read the various threads here for more of the bleak details. Use "freeze" or "crash" or "sleep" for some of your searches. -- You will find that there are very many in the same boat, and we are all looking for answers.