Flea power could be the cause of this issue you have. Sound like your laptop is fine but the screen is not turning on. Follow these steps below:
Turn the laptop upside down, loose the screws using screw driver then locate and disconnect the wire that connects battery and motherboard. Please be very delicate about it. Remove the battery then press power button for 30 seconds.
It will consume all the flea power left in circuits.
Then assemble the laptop as it was before and you are good to go. If you want more details follow this https://error24x7.tips/fix-laptop-screen-not-turning-on/