Crashing iMac (Black screen or spinning beach ball)

Hi, I would consider a complete erase & install then the Upgrade...L

Yes, I'm having exactly the same problem - so annoying. I get either a black screen, a white screen, a blue screen or a scrambled screen (see http://twitpic.com/204ye3). I reckon it's a hardware problem.

Time to take it in, I think.

I am experiencing the same problem and decided to take mine in to get serviced...after waiting about an hour while one of the genius bar guys to run a couple tests he told me to do a reinstall of snow leopard. According to him they couldn't take the computer in for repairs because we couldn't get the problem to replicate while I was there.

Has anybody had any luck reinstalling snow leopard....I am currently in the process of locating my install DVD's and hope there is an easier solution out there.

We have had this issue now for a few weeks. Once the computer goes to sleep, it's just a matter of seconds or hours, but it will freeze. I've tried everything I could think of after reading the posts... SMC, PRAM...

It all started a few weeks back. We had 10.4.x on the machine and it was slow and erratic after a power outage in the middle of a sync, but the screen was never going dark. We brought the machine to the Genius bar. We had a lot of corrupted files, but nothing dramatic according to them. We got the hard drive "erased" and the OS 10.6.3 installed. Came home, re-installed everything else, including all the upgrades to 10.6.4. Next day, we started to have black screens, white screens and screen with lines across.. The machine seems to be running fine in the background, but no screen...

We brought it to the genius bar a second time. THey held it for a week, did all kinds of hardware tests and came clean. We re-installed 10.6.3 and sure enough, brought it back home and this time reloaded everything from time machine and re-upgraded to 10.6.4. Sure enough, next day, back to black, white or frozen lines.

I then decided to re-install the OS from the DVD after erasing the hard drive and re-intall every of my files and programs from disks, thinking the time machine might have caused a problem. Sure enough, once again after all said and done, got the white, black or lines...

I then thought about the peripherals and reverted back to a cord mouse and keyboard. Same....

Guys, if you have any other idea, please let me know. This is frustrating. I had zero problem with this machine for 3 years, and now it's a nightmare.

Thank you!

I am just recently having a similar experience with my i7 iMac. First noticed it while gaming: Call of Duty. It would crash hard to a black screen. By the way, as reference, it has never crashed to anything but a black screen. I reinstalled the 10.6.4 combo but to no avail. I've run Disk Warrior and everything else I have in my array, but nothing seems to work. I will say that I did not experience this problem until AFTER the latest security upgrade. Again, any thoughts would be appreciated.

i'm in the same boat as you guys.
imac i7 with all the latest updates. i get the spinning beach ball all the time and nothing responds, i have to just push the power button til it shuts off. This machine has run fine until i installed snow leopard and everything started to become slower and less responsive. Expose works when it wants to for example.
I used disk utility and did a disk repair after it was said it was needed and its still getting the spinning ball. this is really annoying, i hope they fix this with an update soon.

I have the same problem on my 20" Alu iMac. I get the frozen screen where I can move the cursor but that's it. Sometimes music will continue until I click the mouse and then it to grinds to a halt. Other times the screen goes to black, or I get a psychedelic screen made from dancing horizontal stripes. This has been going on since 10.6.3, sometimes minutes apart, sometimes days. I have taken it to the Genius bar several times and they have run every test available, but without finding fault. I have now replaced the HD and re-installed Snow Leopard and absolutely nothing else. No peripherals attached. The problem continues.

I'll throw my hat in the ring for this. Occasionally (once a week usually), my iMac's screen will just black out. No errors thrown, music will continue playing if it's on. Only solution is to hard reboot the computer. This persists across any scans or diagnostics, and across full OS re-installs as well. Definitely an annoyance with an otherwise perfectly working computer for 3+ years.

Same here. I have an original intel iMac 1.83 ghz Core Duo that was upgraded to OSX 10.6. It has 1gig of RAM.

I haven't put my finger on when it happens, but it appears to be a problem when I've been away from the computer for a while and it's gone to sleep. It won't wake up, just a black screen and beach ball.

Model Name: iMac
Model Identifier: iMac8,1
Processor Name: Intel Core 2 Duo
Processor Speed: 2.4 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache: 6 MB
Memory: 2 GB
Bus Speed: 1.07 GHz

I've just received two of these in my shop from two separate users. I've reformatted them, re-installed the OS, several times but same sluggish responses after about an hour of use on each system. I've run the disk utility, no errors. I've booted with the "command+D" option and no errors. I've reset the PRAM and so on. Only one constant with each, when I run the permissions using the disk utility, there are some issues that cannot be resolved. Same on both systems. This is after the updates, not at the initial install so it's something to do with some of the OS updates for both 10.5 and 10.6 since I've tested both OS's on the machines with two separate sets of install DVD's. Something is up and I expect to receive more of these with similar issues. Just my 2 cents on it.

I've got the same issue. My iMac has been doing the same thing for the past 6 months, it was purchased in 2007. It is so very very frustrating. The screen will go grey (sometimes with a vertical black line in the middle) or black or blue and I unplug it to revive it. I took it to the Carbon (local Apple repair) and they tested it for 24 hrs - no problem! I had them replace the hard drive anyway since it was a bit small...still crashes!! I have done all the updates, run OnyX, added RAM (3GB).... but the computer still crashes.
Basically I am thinking that I trade it in for a new one or move back (gasp!) to PC! Any more suggestions? Could this be a logic board issue?

Okay first...PUT THE PC DOWN AND BACK AWAY SLOWLY....If a Mac going to a black screen is enough to make you switch to a PC, you obviously have never used a PC.

Now, as for me, I reported the problem a few days ago about my 1stGen Intel iMac going to a black screen and beach ball, and not waking up. I decided that this was the perfect opportunity to erase the hard drive and reinstall Snow Leopard from scratch, as I'd collected about three or four years of junk that really needed to get off the computer.

I am happy to report that, so far, the reinstall has solved the problem AND with all the garbage gone the computer now runs much quicker.

I have a feeling that the black screen problem was due to certain prefs conflicting with Snow Leopard. For example a while back I'd tried out a free version of Living Desktop screen saver and, though I'd uninstalled it, I must not have done so successfully because there was still an icon for it in System Utilities and one of the Hot Corners was still directed to start the screen saver even though it no longer existed.

So, long story short, consider a fresh install of the OS after wiping the drive. You're probably thinking "dear lord, I have way too much stuff on the hard drive to wipe it". well, if you're gonna buy a new computer, you'll effectively be doing the same thing...starting from scratch. And the purging will do wonders.

I have reinstalled Snow Leopard a couple of times - did not "wipe the hard drive" i.e. reformat it, though. Doesn't help. Wouldn't I just get the same problem once I reinstall my apps and files? I use a Time Capsule backup.
OK - I put the PC down and backed away.....whew, that was close.

Yes, exact same problem for the past few months. Any developments on this? Any solutions? It's driving us nuts.

OK. I think I've solved it!

I downdated back to Mac OS X 10.6.0 with my Snow Leopard Install DVD and then downloaded the 10.6.5 Update Combo http://support.apple.com/kb/DL1324 - the problems began straight after the 10.6.6 update.

Now it all works again. No more freezing display, but with without 10.6.6 - no more App Store (luckily, I can use it on my MacBook and transfer the purchases to any Mac that uses the same iTunes account).

Just remember to turn off automatic updating in Software Update and set it to ignore the Mac OS X updates, or else...