What can I do to fix this problem?

These are some of the methods you can follow-

Hard reset — unplug charger, remove battery (if removable), hold power button 30 seconds, reinsert and try again.

Check the charger — try a different cable/adapter or check if the charging port light comes on.

Force power on — hold power button for 15 seconds straight, some laptops need a long press.

Check for signs of life — listen for fan spin, keyboard lights, or HDD sounds to narrow down the issue.

Connect to external monitor — rules out a screen-only failure.

Remove external devices — unplug all USB drives, mice, and peripherals that could block boot.