How to fix my old MacBook Pro Blank screen?
how to fix my old mac Blank (empty) screen
[Re-Titled by Moderator]
There's several types of screens that may appear; when the Mac fails to fully startup.
These may have actionable meaning; and can be blank, black, white; among others.
• If your Mac starts up to a blank screen - Apple Support
https://support.apple.com/en-us/HT210905
If your Mac seems to be turned on but nothing appears on your display,
determine whether you're using a Mac with Apple silicon, then follow
the appropriate steps; to determine next course of action.
(See either Apple silicon -&/or- Intel-based Mac instructions next.)
• Mac White Screen? How to Fix a White Screen on Boot | osxdaily
https://osxdaily.com/2016/12/10/mac-white-screen-boot-fix/
Other things to try include Safe mode on startup, instructions vary
depending the build version of Mac, and version of hardware, etc.
• How to use Safe mode on your Mac - Apple Support
https://support.apple.com/en-us/HT201262