Gray screen appears on iMac during startup – and how the problem was solved

Subtitle: the usefulness of a backup

On Friday I just had to print out a document on my iMac at home. When I wanted to start it, the well-known gray screen appeared – and didn’t disappear anymore… But I needed this document really instantly. The first thing I could do, was to plug the external hard disk with my backup into my laptop (MacBook Air). And to my surprise I didn’t have to restore it to my too small hard drive, but could browse through the files on the HD and finally found the needed document, opened it on my laptop and printed it out. Mac’s backup system Time Machine is really very useful, indeed…

The next day I tried all the steps recommended by Apple’s support on the page Mac OS X: Gray screen appears during startup in order to fix the problem.

• I performed a safed boot – but it didn’t help.
• I reset the NVRAM / PRAM – but it didn’t work.
• I restarted from the install disk and performed a disk check and a disk repair – but the gray screen reappeared again.
• I checked cables and power source, removed all devices, but had no third party RAM or internal hardware to remove.

So, there was only one thing I could do before buying a new PC: 

• I inserted the utility disk, performed an erase of the hard disk and a new installation of the system from the backup.

I didn’t really believe that this could help. And I was glad to use Time Machine really seriously every day. So I didn’t risk a data loss when the operation went wrong (after erasing the HD). The procedure took four hours – then came the moment, when I restarted my iMac – and there was the login window! I could login, the system started as nothing ever happened… I just had to update some settings (E-Mail, Dropbox, iTunes) and I could postpone buying a new PC 😉

So have you already made a backup of your system today?