If you only see a gray color on the screen while booting your Mac and remains so without being able to get into the system, that is called Break Down Mac Grey Screen at Startup. And this is how to resolve it.
First detection, Disconnect Your peripherals
- Start by turning your Mac off. You will need to press and hold your Mac’s power button to force your Mac to shut down.
- Disconnect all of your Mac’s peripherals, except the keyboard, mouse, and display. Be sure to disconnect any Ethernet cable, audio in or out cables, headphones, etc.
- Start your Mac back up. If your Mac starts back up without issue, then you’ll know that it’s a problem with a peripheral. You will need to shut your Mac back down, reconnect one peripheral, and then restart your Mac. Continue this process of reconnecting one peripheral at a time and then restarting your Mac until you find the bad peripheral. Remember that the problem can also be a bad cable, so if you plug a peripheral back in and it causes the gray screen issue, try the peripheral with a new cable before you replace the peripheral.
If you still have the gray screen issue after reconnecting all of your peripherals, the problem could be with the mouse or keyboard. If you have a spare mouse and keyboard, swap them with your current mouse and keyboard, and then restart your Mac.
How if peripherals Not at Fault
If no peripheral or cable appears to be at fault, there are still a few possible problems with your Mac that can cause the gray screen to occur.
- Disconnect all of the peripherals, except the mouse and keyboard.
- Start your Mac using the Safe Boot process.
During the Safe Boot, your Mac will perform a directory check of your startup drive. If the drive directory is intact, the OS will continue the startup process by loading only the minimum number of kernel extensions it needs to boot.
If your Mac successfully starts up in Safe Boot mode, try restarting your Mac again in normal mode. If your Mac starts and makes it to the login screen or the desktop, then you’ll need to verify that your startup drive is working correctly. Chances are the drive has some issues that need to be repaired. You can use Disk Utility’s First Aid tools to check and repair your drive; you may even need to be replace the drive. Good thing you have a current backup, right?
If you’re unable to start your Mac in Safe Boot mode, or your Mac starts in Safe Boot mode, but it won’t start up normally, you can try the following:
- Reset PRAM
- Reset SMC
Once you reset the PRAM and SMC, try starting up your Mac. Peripherals other than the keyboard and mouse should still be disconnected.
If your Mac starts up normally, you will need to reattach your peripherals one at a time, restarting after each, to verify that none of them caused the original gray screen issue.