macOS · Mac · Everyday fixes

Reset NVRAM when things misbehave

NVRAM stores display resolution, sound and boot preferences. A reset fixes a surprising number of weird glitches.

DifficultyEasy
Time3 min
RiskLow
ReversibleYes
PlatformmacOS
UpdatedSep 22, 2026

Written and tested by emdottech

What that means

Low risk. This fix only checks things, or changes settings you can switch back in the same place. This change is reversible — you can return to the previous state without professional help or data loss.

The NVRAM reset sequence — press power, immediately hold Command Option P R for about twenty seconds

Steps

01
- Shut the Mac down completely — not sleep, a full shutdown
02
- Press the power button, then immediately hold OptionCommandPR together for about 20 seconds
03
- On older Macs you'll hear the startup chime twice; on newer Intel Macs the Apple logo appears and disappears a second time — either is your cue it's done, then release the keys
04
- Let the Mac boot normally
05
- NVRAM also resets display resolution, startup-disk choice, time zone and speaker volume to defaults, so reselect your startup disk in System Settings or turn sound back up if needed
06
- If the same glitch comes straight back, NVRAM wasn't the cause — check the specific device (display cable, audio output) instead

How to verify the fix

The Mac boots normally and the resolution/audio glitches that prompted the reset are gone.

If this didn't fix it

Glitches return after a normal boot — NVRAM wasn't the cause; check display settings and audio output next.

Next stop: the related fixes below, or start a guided diagnosis.

Still stuck? Diagnose my problem Browse all Mac fixes

Reset NVRAM when things misbehave

Steps

✓How to verify the fix

!If this didn't fix it

Related fixes

How to verify the fix

If this didn't fix it