I'd replace the screen, it looks terminal to me.
You can get most screens off ebay for a little under $100. If your lucky, there's a utube video on how to dismantle your model enough to get the screen out. There's normally just one flexible ribbon cable going into a locking connector on the screen. Normally a flap on the connector flips up to unlock the cable. Some older ones have a separate DC cable running to them. Probably older LCD screens.
This video looks close?
https://www.youtube.com/watch?v=VbFBDcqchec
I done several and never had to remove a keyboard but I've never done a Dell or HP either so who knows
