If your Mac starts up to a blank screen - Apple Support

Do you see the MacBook black screen of doom? Here's how to fix it

Mac Has a White Screen on Startup, How to Fix?

How To Fix MacBook Black Screen With Colored Lines- The Mac Observer

If your Mac doesn't start up all the way - Apple Support

Why your Mac has the white screen of death, and how to fix it

A Detailed Guide to Fixing Mac Booting With Black Screen Issues - Guiding Tech

Have your Mac speak text that's on the screen - Apple Support

Mac Is Frozen: Why It Keeps Freezing & How to Unfreeze Apple Computer?

If your iPad doesn't respond - Apple Support