iMac does not boot (start)

iMac does not boot (start), instead displays GRAY, BLUE or BLACK screen.

If this happens, there has been a severe issue on the MAC's hard drive.

This happens most of the time if there has been a sudden power outage, or the iMac was shut down by pulling the power plug instead of shutting it down properly.


Only two things to try in this case:

  1. Unplug the power cord from the back of the iMac.
  2. Press and hold the powerbutton for more than 5 seconds. This will drain the motherboard's capacitors of all energy, resetting all components.
  3. Reconnect the power plug, take a deep breath and push the power button normally to turn on the iMac.

If this solved it, and after max. of 15 minutes the MAC desktop comes up, good.

Why 15 minutes? This is the maximum time it should take the iMac to check the hard drive for errors. It normally does this during startup showing a gray screen with a rotating gear.


The second thing you can try if the iMac is stuck at a blue or gray screen only:


  1. Make sure the iMac is turned off.
  2. Press and hold the SHIFT key on the keyboard.
  3. Turn the iMac back on, while still holding down the SHIFT key.

This attempts to boot the iMac w/o any plugins or extensions you might have installed or which might have been corrupted due to power-outage, etc.

If this was successful, the Mac OS X Desktop should show up within max. 15 minutes.

If not, sadly, we need the MAC back to further troubleshoot the cause. Please give the tech department a call.


Finally, a black screen with some writing on it in several different languages is bad news. Nothing to do or troubleshoot there anymore, we need the computer back. Please call the Tech Department and we will arrange a computer exchange.


Please read "Shut down an iMac properly" to avoid this issue happening with your replacement Mac.

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