HT204267: If your Mac won't turn on

Learn about If your Mac won't turn on
ron4245

Q: My iMac screen turns gray before fully loading when starting up.  Any suggestions?

I have an iMac that was purchased in 2011.  I received a notice to update some software.  iOS was one of them.  After selecting update it came back and aked to restart.  I selected yes.  I left the room.  When I came back, the screed was gray with the cursor arrow in the upper left.  It moves but there is no video.  I have tried all of the following:

turned off and back on

turned off and held the power button for 10 seconds while it booted

turned off and disconnected everything.  After reconnecting the power chord after 30 seconds turned it on

turned off and back on while holding the command and R key while it rebooted

 

In all cases the result is the same.  I can hear the internal fan and drive.  The apple logo comes up for maybe 20 seconds and the booting progres bar moves to about 1/3 the way.  Then the screen goes gray with the cursor in the upper left.

 

Any suggestions?

iMac (27-inch Mid 2011), OS X Mountain Lion (10.8.2)

Posted on Aug 22, 2015 5:33 AM