My Apple iPad ran out of battery, and even after charging it for a while, it remains unresponsive. Why won't my iPad turn on?

You may encounter issues where it refuses to turn on, displays a black or frozen screen, or gets stuck on the Apple logo during startup. When faced with these challenges, it's important to know how to troubleshoot and potentially resolve them:
Black or Frozen iPad Screen Troubles:
• Without Home button iPads:
Release the volume up button (next to the top button) quickly.
Quickly press and release the volume down button (farthest from the top).
Hold the top (power) button until your iPad restarts.
If your iPad remains unresponsive, charge it for an hour before trying again.
• For Home-button iPads:
Press and hold the Home and power buttons until the Apple logo appears.
If your iPad remains unresponsive, charge it for an hour and try again.
• For iPads with a Home button:
iPad Startup Stuck on Apple Logo:
Computer-connect your iPad. Launch Finder on macOS Catalina. MacOS Mojave or earlier, or PC, open iTunes.
Computer-identify your device.
• Without Home button iPads:
Quickly release the volume up button.
Quickly release the volume down button.
Hold the power button until your device restarts. Keep holding.
• For Home-button iPads:
Hold the Home and top buttons (power buttons).
Hold the buttons until the recovery mode screen appears.
When asked to restore or update, choose "Update."
Your computer will download iPad software. If this takes more than 15 minutes, your iPad may exit recovery mode, requiring steps 2-4 again.
All these above are suggestions. It’s better to ask Apple support for detailed guidance.