Recently, I attempted to re-install Mac OS X Lion on my 2007 iMac computer (EMC 2133), but during the installation process it got interrupted. After rebooting it just displays a blank grey screen with no apple. I think there is a problem with the firmware, because because here are steps I have taken to attempt to resolve the issue, which have not appeared to work:
- Boot using the Mac OS X Lion DVD by holding C. Screen remains blank.
- Boot into hardware test by holding D. Screen remains blank.
- Boot into safe mode test by holding shift. Screen remains blank.
- Attempt to choose boot device by holding option. Screen remains blank.
- Boot into single user mode by holding Command - S. Screen remains blank.
- Reset parameter RAM by holding option - Command - P - R. Hold until system reboots at least three times, but after rebooting again the screen remains blank.
- Boot using Disk Warrior 4.4 DVD by holding C. Screen remains blank.
- Boot using Tech Tool Pro DVD by holding C. Screen remains blank.
- Taking out the hard drive and re-initializing it on my older eMac with Mac OS X Panther. The hard drive re-initializes OK but it doesn't change anything else, so it appears to be a firmware issue.
- Boot into Apple Firmware Restoration CD 1.3 by holding the power button for a long time according to this link https://discussions.apple.com/thread/3962770?start=0&tstart=0. I don't see the 3 quick blinks followed by 3 slow blinks then 3 quick blinks of any LED or tones, but instead hear one long tone and the computer starts up. I put the firmware restoration CD into my DVD, but the screen remains blank.
A year or two ago I had installed rEFIt on my Mac and had it successfully booting to various devices. At that time I think I had Mac OS X Lion installed. At some time later I removed rEFIt and installed Mac OS X Mavericks, which worked without a problem. Then a few days ago I decided to try reinstalling rEFIt (I should have probably used rEFInd instead, but rEFIt had worked previously for me, so that is why I had tried to use it again). This is when I started having issues with booting into my iMac, but even removing rEFIt and re-initializing my internal hard drive has not resolved the issue.
Does anyone have any suggestions? Is there anything else I can do to fix my iMac? TIA.
Please note that I clarified the steps I took for firmware repairs in step 10.
OK, I now see from here https://support.apple.com/en-us/HT202768 that the long tone from step 10 means that an EFI update is in progress, but even if I leave the computer on for a long time, the update does not appear complete. How long should it take? How do I know when it has finished the update?