You need to test the screen. Connect the laptop to an external screen, such as a tv via an HDMI cable.
Turn on the laptop, wait 5 minutes to make sure it loads, than press the "Fn" key and the "F4" together to switch the laptop to external video output. Make sure the tv is set to the appropriate input source. If you get a picture on tv, than laptop is working but not outputting to internal screen. This will determine what needs to be done next.