imac 27 late 2013 black screen on startup random

Use the Disk Utility to make repairs by following these instructions:

In the Startup Manager, use the arrow keys to select the main drive (usually called Macintosh HD), and then press the ReturnĪfter your Mac successfully starts, go to System Preferences and adjust any settings that changed.Ī faulty hard drive can cause a white screen to appear.

Restart your Mac, then press and hold down the Option.

If your Mac starts normally, then you can skip the instructions below. If your Mac has multiple drives, you might need to select a start-up disk after resetting your Mac.

Wait for the Mac to finish starting up.

Continue to hold down the keys mentioned in the previous step until you hear the second start-up chime, then release the keys.

Restart the Mac, then press and hold down the Command + Option + P + R keys when you hear the start-up chime.To reset the PRAM/NVRAM, follow these instructions: Parameter Random-Access Memory (PRAM) and Non-volatile Random-Access Memory (NVRAM) store configuration information about your Mac. The all-in-one disk cleaning manager - available for free for Windows and Mac - lets you visualize, manage and reclaim your storage space in just one click, ensuring your computer runs like a dream. If the Mac can start up successfully, use Cleaner One Pro to remove junk files (like app logs and caches), unneeded big files, and duplicates. Once the Mac has gone into Safe Mode, go to your Applications folder to uninstall the apps that you no longer use, then empty the trash.Release the shift key when you see the Apple logo and progress bar.Press the power button, and then press and hold the shift key when you hear the start-up chime.To start your Mac in Safe Mode, follow these instructions: Start your Mac in Safe Mode and clean it up. If the instructions above did not solve the problem, proceed to the next step.Ģ.

If your Mac starts normally, then you can try reconnecting all of the devices one at a time until you find the one that caused of the problem. After you have done that, restart the Mac and see if the white screen reappears. To find a malfunctioning device attached to your Mac, start by disconnecting everything from it, including peripherals with a Bluetooth or other wireless connection. Check your Mac’s hardware systematically. Follow the steps below to solve the problem.ġ. If a plain white screen appears when your Mac starts, then some of its hardware or software may have failed.

Imac 27 late 2013 black screen on startup random