On MacBook Air keyboards, the Caps Lock key has a built-in delay mechanism — it requires a firm, deliberate press (slightly longer than a normal keypress) to activate. This is by design in macOS to prevent accidental caps lock activation.
Here are a few things to check and try:
1. Check Caps Lock settings:
- Go to System Preferences > Keyboard > Modifier Keys
- Make sure Caps Lock Key is set to "Caps Lock" and not "No Action"
2. Try a firmware reset (SMC reset) — this can resolve keyboard backlight and key responsiveness issues:
- Shut down the MacBook Air
- Hold Shift + Control + Option on the left side of the keyboard, then press the Power button simultaneously
- Hold all four keys for 10 seconds, then release
- Power on the Mac normally
3. Reset NVRAM/PRAM:
- Shut down the Mac
- Power it on, then immediately hold Option + Command + P + R
- Keep holding for about 20 seconds (you may hear the startup chime twice)
- Release and let it boot normally
4. Check if the issue is software-related:
- Create a new user account (System Preferences > Users & Groups) and test Caps Lock there
- If it works in the new account, there may be a software conflict in your main profile
5. Physical inspection:
- If the key does not physically depress properly or feels stuck, there may be debris under the keycap. In that case, Apple Store or an authorized service provider can inspect it.
Note: macOS Sierra (10.12.6) is no longer supported. If none of the above helps, upgrading to a newer supported macOS (if your hardware allows) could resolve underlying keyboard driver issues.
