Plug in the charger and wait a few seconds
Open the laptop lid fully
Press any key on the keyboard
Press the touchpad button or click the touchpad
Connect an external keyboard and press its power key if supported
Use the motherboard power-on pins if the laptop is disassembled and you know the correct pins
Enable power-on from AC in BIOS/UEFI if the setting is available
Enable wake-on-LAN if the laptop supports network power-on
Use a docking station power button if the laptop supports it
Replace or repair the broken power button if none of the above works