Problem
If your Mac is having any of the following issues, try running Safe Boot first and if that does not work, try Single User Mode as detailed below.
- Flashing question mark appears when trying to boot
- Gray screen with a stuck or always showing progress bar
- White or Blue Screen upon boot
- Unable to repairing permissions
- System is running extremely slow
- Unable to log in
Cause
Corrupted Hard Drive, lost settings or files amongst may other issues.
Solution
Warning: Singer User Mode runs as the “root” user and you should be careful not to run any other commands other than those stated.
- Turn you Mac off if it is on. You can also hold the power button down until it shuts down if needed.
- Press the power button and the immediately press the Command (cmd) and the S key together and hold til you see a black screen with white writing.
- If the Mac got into Single User mode successfully then you will see the following at the bottom of the screen:
“If you wish to boot the system: Exit”
“:/Root#” - Type this command in exactly as you see it here (with a space between the k and –), then press Enter:
fsck -fy
If it comes back “command not found” then try again and check the spelling and spacing.
- Once you have done this, you will have white text scroll down the screen.
- If the machine is fine or cannot find the issue it will say at the end:
“The Volume Macintosh HD appears to be OK.” - If it does find some issues, you will get either of these messages:
“Macintosh HD has been repaired.” or ”Macintosh HD has been modified.”
It may give additional details with what have caused the issue if the drive cannot be repaired.
- If the machine is fine or cannot find the issue it will say at the end:
- If you get the any errors then you can try running Step 4 again a few more times.
If these steps do not work then it may need to have the operating system re-installed or a repair carried out by Apple.