MacBook keeps turning off after start up?

Xstitch13 wrote:

my macbook keeps turning off right after start up. the only way to keep it on is to hold down control option command. how do i fix it?

Try a SafeBoot https://support.apple.com/en-us/HT201262

Takes noticeable longer to get to the login screen, does a 5 minute disk repair before it fully boots up, and certain system caches get cleared and rebuilt, including dynamic loader cache, etc.

Login and test. Reboot as normal. Caches get rebuilt automatically

if not insight or resolve—

Boot into Internet Recovery (Option Command R) and from the dropdown menu: Utilities>  Disk Utility> run the First Aid on your Macintosh HD (and the "Macintosh HD-Data" volume as well if Catalina/Big Sur) If errors are found and repaired, run again until no errors reported.

Disk Utility>View>Show All Devices The best sequence is —

• Volume level

• Container level

• Parent drive

Recovery: https://support.apple.com/en-us/HT204904

How to reinstall macOS from macOS Recovery - https://support.apple.com/en-us/HT204904