Macbook turns on but screen is dead or completely dark
Apple has an excellent process to triage macs that don’t boot all the way.

If you hold the option key or boot to internet recovery, you should see things on the screen even if there is no drive present, no OS present so you can know you need a repair if you can’t even see internet recovery like here: https://support.apple.com/en-us/HT204156

In the end, you will have a working Mac again - possibly reinstalling the OS or erasing and then reinstalling or you take it in for service since there is a hardware issue.

Start here and ask a follow on question with exactly where your troubleshooting led you.


https://support.apple.com/en-us/HT204267