iMac refusing to boot

Question

iMac refusing to boot

Hi,

I had a nasty surprise this morning with my iMac (white iMac, C2D, 24"): I powered it up, the fans started blowing like crazy, and then it just powered back down. Nothing else, no display, no startup sound, just that. When I tried to turn it back on, it wouldn't do anything at all. I finally had to pull the power plug, put it back in, and it started again.

I'm wondering if this could come from the dust that accumulated inside the iMac. I'm already having problems due to the fans not cooling the CPU and GPU enough, so I had to increase the fans' speed to compensate. When not doing that, the screen goes crazy and displays weird lines everywhere, until it finally just crashes.

Could it be something else, or just using a vacuum cleaner to remove some dust would solve it ?

iMac C2D 24" (white), Mac OS X (10.6.2)

Posted on Apr 6, 2010 6:27 AM

Reply

Answer 1

Dah•veed

Level 9

66,727 points

Apr 6, 2010 8:00 AM in response to Fred Leboucher

Last summer during a repair on my iMac Core Duo I was shocked how dirty they get. Perhaps paying a tech to open it and clean it out would be helpful.

You might also reset the Systems Management Controller;
• Shut down the computer.
• Detach the computer's power cord.
• Press and hold the power button for 5 seconds.
• Release the power button.
• Reattach the computer's power cable.
• Turn on the computer.

Dah•veed

Reply

Answer 2

Apr 7, 2010 10:13 AM in response to Fred Leboucher

HI Fred,

Since you are experiencing startup problems, make sure your important data is backed up to an external source just in case.

If your iMac has trouble starting up again, try Resetting the PRAM

the screen goes crazy and displays weird lines everywhere, until it finally just crashes.

Try the Apple Hardware Test

Might be a good time to boot from your install disc, run Disk Utility to make sure there aren't errors on the startup disk.

Insert your install disk and Restart, holding down the "C" key until grey Apple appears.
Go to Installer menu and launch Disk Utility.
Select your HDD (manufacturer ID) in the left panel.
Select First Aid in the Main panel.
*(Check S.M.A.R.T Status of HDD at the bottom of right panel. It should say: Verified)*
Click Repair Disk on the bottom right.
If DU reports disk does not need repairs quit DU and restart.
If DU reports errors Repair again and again until DU reports disk is repaired.
When you are finished with DU, from the Menu Bar, select Utilities/Startup Manager.
Select your start up disk and click Restart

While you have the Disk Utility window open, look at the bottom of the window. Where you see Capacity and Available. *Make sure there is always 10% to 15% free disk space*

If you cannot boot from your install disc, try booting in Safe Mode

Carolyn 🙂

Reply