I’d probably chalk it down to either a corrupted BIOS or a faulty video cable, but I’m not sure which one. Try connecting an external monitor to your laptop and then booting the PC, to see if it works.
Next, try and see if you can find an update for your BIOS and any updates for your laptop in general. The rebooting will be problematic for the update, so try to avoid it if you at all can.
After that, remove the hard drive and then try to boot the laptop. If that doesn’t work, remove each one of the RAM sticks to see if it is a RAM problem, then remove all the RAM sticks to see if the RAM boot error comes up (the laptop will start beeping).
Finally, see if you can replace the laptop screen. This might not work, so I don’t recommend it, but try and find a replacement online and see if you can switch it out. At that point it might just be earlier to bring it to a repair shop.
I hope this helps!