Reinstall OS X by booting from the Recovery HD using the Command and R keys.Download and install the OS X El Capitan 10.11.6 Combo Update or 10.12.6 Combo Update or Download macOS High Sierra 10.13.4 Combo Update as needed.If your problems cease, then consider switching to the new account and transferring your files to it - Transferring files from one User Account to another. Upon completion log out of your current account then log into the new account. On the left under Current User click on the Add button under Login Options. Click on the lock icon and enter your Admin password when prompted. Create a New User Account Open Users & Groups preferences.Repair permissions on the Home folder: Resolve issues caused by changing the permissions of items in your home folder.Restart the computer from the Apple Menu. Quit Disk Utility and return to the Utility Menu. Click on the First Aid button in the toolbar. Select the indented (usually, Macintosh HD) volume entry from the side list. Choose Disk Utility and click on the Continue button. Immediately after the chime hold down the Command and Rkeys until the Utility Menu appears. Repair the disk by booting from the Recovery HD.Use Apple Hardware Test to see if there is any hardware malfunction.Test in safe mode to see if the problem persists, then restart normally. Reset your Startup Disk and Sound preferences.Reset the System Management Controller (SMC).Disconnect all third-party peripherals.Shutdown the computer, wait 30 seconds, restart the computer.You should try each, one at a time, then test to see if the problem is fixed before going on to the next.īe sure to backup your files before proceeding if possible. If they claim it still works in your version of macOS then see the following:Ī Troubleshooting Procedure that may Fix Problems with macOS El Capitan or Later Unless they state otherwise it is their fault, not Apple's.

How to install brother printer on mac