What is the issue? Will I need a new screen and is it covered?

I'm attaching a few pictures below, please read all the information and view the pictures, I really need some advice. Your time and help is really appreciated.

Picture 1: https://imgur.com/a/piZjz

Picture 2: https://imgur.com/a/ULV0s

Picture 3: https://imgur.com/a/WFdcD

Ok, so earlier, I closed my device and opened it again and all these coloured lines were over my screen. Initially I thought, shoot, I must've closed something in there, but when I closed down my computer, there was no visual damage, at all. I therefore thought it must've been a something loose with the GPU/CPU, I tried running tests but couldn't see the results. Sometimes when I was doing a test, the screen would go black and the coloured lines and dot in the middle would remain. (Picture 2/3). When booting, there is a background but it goes black when I login as shown in Picture 1 and 2 respectively. What do you think the problem is? I'm pretty sure this isn't accidental damage and rather a fault with the computer. Do you think it will be covered by warranty? Thanks for anyone's help.