Dr Mac’s Rants & Raves
Episode # 397
In the first installment, I recommend three techniques that solve many (if not most) problems with recalcitrant Macs: restarting, running Disk Utility first aid, and booting in Safe Mode. If your Mac is still wobbly after trying them, here are some other tips you can try:
Zap the PRAM / NVRAM
Sometimes your Mac’s Settings RAM (PRAM) or Non-volatile RAM (NVRAM) – small chunks of memory that aren’t erased or forgotten when you shut down or restart – get corrupted or scrambled. They remember settings like time zone, startup disk, speaker volume, kernel panic info, etc.
To reset (often called zapping) your PRAM / NVRAM, restart your Mac while pressing Command + Option + P + R (yes, that’s four keys – use your nose if you have to). Keep pressing until your Mac reboots twice, then release them and restart normally.
Note that your startup disk, time zone, and sound volume may be changed after zapping. If so, launch System Preferences and reselect the startup disk, time zone, and sound volume you prefer.
If zapping your PRAM / NVRAM doesn’t cure your Mac’s ailments, it’s time to try stronger drugs. If nothing I’ve suggested so far has done the trick, there’s one more thing to try: reinstalling macOS. I saved it for the end because it takes the longest and is more complicated than the other techniques. Fortunately, Apple has an interesting tech note on reinstallation at https://support.apple.com/en-us/HT204904.
Follow Apple’s instructions, being careful not to erase your drive before reinstalling macOS. As long as you don’t erase your drive before reinstalling macOS, you won’t lose any data. You simply install a fresh copy of macOS, which shouldn’t affect your files, settings, or anything else. Even so, I recommend a full backup of your startup disk (if possible) before trying it.
Before throwing in the towel …
If none of what I suggested fixes your problem, here are two more things to try before seeking professional help:
Unfortunately, if your Mac is still acting abnormally after trying everything in both parts of this column, your problem is likely hardware related and will require professional diagnosis and repair. It’s time to call the Apple hotline (again), visit an Apple Store (currently not possible due to Covid-19), or take your Mac to an independent Apple service provider.