Sounds like someone set a Firmware Password or there is a hardware issue.
Booting From An OS X Installer Disc
1. Insert OS X Installer Disc into the optical drive.
2. Restart the computer.
3. Immediately after the chime press and hold down the "C" key.
4. Release the key when the spinning gear below the dark gray Apple logo appears.
5. Wait for installer to finish loading.
What happens, precisely?
This is for those of you who've tried to find out how to do away with the gray padlock of death. You have to install the original OS disc that came with your computer. Insert it and go to Mac installer, under Disk Utilities to the drop down menu. Then go to about the fourth one down marked Firmware Password. When you do, it just turn off the password portion of it and you won't need to enter any password the next time you install or reboot from your DVD/CD disc. But just be aware that in doing this, anyone can login into your OS. Hope it helps. ~Kathryne
This is the same screen that I keep seeing. I've owned this white iMac since 2008 (late 2006 model) and I updated it last year, to Lion, then moved to my new house and couldn't log in. I placed it aside and now I really need data off of it. I turn it on, regardless of what I do I'll see the login screen with my picture, no menus and the password won't take. I've been able to get it to the grey lock screen and tried the password (plus some) and nothing. I know the computer works fine, maybe I've tried the password too many times. I tried the Firmware pw removal from apple documents without success, memory as well. Any suggestions without lugging it to the apple store, please do assist. I swear I thought I would have been able to reset the pw with my apple id but no, it won't seem to have the option. scratching my head often. I tried target disk mode, lock screen.
Also, I have all of the manuals, books, cds, etcetera from when I purchased, I've tried all of the original install disks and tried Lion Combo, I ordered the Lion CD (AGAIN PURCHASE grr) and am waiting for it to arrive however I'm quite certain it won't let me by the lock screen- there is no documentation about this screen online except for here, I've searched all day and found this thread- Thanks !
I was able to do this ! YAY ! I believe I did something incorrectly on the first go with the PRAM reset. I was able to enter Single User Mode with original disk. Yay ! It was indeed the firmware password! Thank you Kappy !
Following Kappy's steps, I did the following;
If you're running OS 9, you may need another mac (though i suspect a PC with firewire and a HFS driver would do) and a firewire cable. You will need to delete preferences pertaining to keychain access and any keychains in the preferences folder in the system holder The first imacs ran this so its plausible
If you're running OS X on the imac
Single user mode would do the trick unless there's open firmware password protection in place
To go into single user mode
- Press the power button to start the computer.
- Immediately press and hold the Command (Apple) key and one of the following: the "s" key for single-user mode. (Command-S) This should boot into a white screen, and iirc throw you into a command prompt
These instructions should work for older versions such as 10.4. Khafshoh S' version works for newer systems 10.5 and better - 10.7 also has yet another option for resetting the password involving the 'resetpassword' command in lion recovery.
Instructions for changing the password are based off of Apple's documentation though the documentation goes very in-depth.
You would then mount the file system as writable with
mount -uw /
then find out what the accounts on the system are with
then change their passwords with
reboot and get back into graphical mode with
Then check the accounts to work out which one is the admin account.