1. Make sure the laptop is properly plugged into a power source.
2. Remove battery and reinsert it into the laptop.
3. Test to see if the power button works after replacing the battery.
4. Clean the power button with a dry cloth.
5. Test the laptop again to see if that worked.
6. If the button still doesn’t work, use a small screwdriver to remove the power button casing.
7. Check the wiring for any damage or corrosion.
8. Replace the power button if necessary.
9. Put the casing back on and test the laptop again.
10. If none of the previous steps worked, consider taking the laptop to a repair shop.