More steps to try before you go to Apple with wonky Mac

week, I offered a handful of quick and easy techniques for troubleshooting a wonky Mac, including restarting, rebooting into safe mode, running

Disk Utility’s First Aid, resetting NVRAM or SMC and running OnyX. These procedures are relatively painless and unlikely to make things worse. If none of them cured what ails your Mac, there are still a few more things to try before you throw in the towel and contact Apple — or whomever — for technical help.

First, disconnect all external devices—hard disks, SSDs, hubs, docks, monitors, printers and so on — from your Mac. Also disconnect your wired keyboard and mouse, if possible. Now reboot and determine whether the problem still exists.

If it does, proceed to the next step. If the problem is gone when all devices are disconnected, one of those devices or its cable is probably to blame.

The next step is to reconnect one external device, reboot and determine whether the problem exists. If things appear to work correctly, connect another device to see if the problem returns. Repeat this process until your external devices are all reconnected.

If the problem reoccurs, the suspect is the last device (or its cable) you connected that’s causing the issue or, at least, part of it. Try a different cable, if possible.

Should the wonkiness still occur after replacing the device’s cable, the device itself is probably the culprit. Contact the manufacturer for support or replacement.

Still having issues after you’ve confirmed that external devices and cables are not involved? The next thing to try is reinstalling macOS (as described in Apple Support article HT204904). If you follow Apple’s explicit instructions, you can reinstall macOS without erasing your disk.

There’s still one last thing to try before seeking professional help if the problem persists after reinstalling macOS: a clean install of macOS (also known as a “nuke and pave”). It’s painful, but it is also likely to cure wonkiLast ness when other techniques fail.

First, make sure you have one or more backups (and have tested them).

Now boot into macOS Recovery, erase your startup disk using Disk Utility and reinstall macOS but do not restore your data yet. Why? Because restoring your data could also restore whatever was causing the problem in the first place. So before you restore, try using your Mac for a while with nothing but a cleanly installed copy of macOS. If things work as expected, you can then use Migration Assistant to restore your data.

If you’re still having problems after restoring your data, perform another clean install (without Migration Assistant) and this time restore your files manually a few items at a time.

If nothing I’ve suggested fixes your issue, I recommend contacting Apple Support at 1-800-275-2273 or www.support.apple.com.