So right now you think the laptop boots normally but your screen is now working? Could you please check with an external monitor or with a TV? You need to confirm if this is a screen failure or a PC issue. If the screen appears normaly on another monitor, you may need to check your laptop’s screen and its connections. If the laptop is under warranty, you may need to contact the seller.
I would suggest you to disconnect the power cable and battery (if possible) and hold the power button for 30 seconds. Reconnect the power cable and try to boot normally. The problem persists?
Hope this helps