Dell XPS 15z (L511z) Discolored screen problem

[Ramahi89]

Hello,
As the title says, its a fairly used old laptop that has been left 4 dead for 6+ years now.

Specs: FHD screen
i7 2620M
8GB Ram
64 bit Windows 7
GPU: Nvidia Geforce GT525M (Optimus) - Intel HD graphics Family

Problem: Screen is discolored when booting the laptop using the normal laptop's screen. however if you open the laptop using an HDMI connection to a TV all is fine on the TV, Laptop screen is not.

Attached are photos of the problem.

I have asked professional help from multiple maintenance shops, and have had multiple answers which got me confused.

1st: Said that the screen ribbon cable has gone bad, and needs replacement.
2nd: Said that the screen should be replaced all at once. (Dell repair shop)
3rd: Said that the GPU (Nvidia) dedicated card has gone bad and needs fixing.

According to your experiences, which of the following describes the best solution?
I am fixing it for backup purposes only.

Thanks

 

[Rdslw]

all 3 are possible, 2'nd might be common and cheap to replace.
I would start with another OS (like boot pendrive linux and check if its not data corruption on drive.)
if linux shows same problem then I would go to bios and try disable/enable onboard/dedicated graphics. Not sure if this laptop will allow that in bios.
if this won't help you can open it yourself and try to reatach LCD cable/ search for possible problems by yourself)
https://www.ifixit.com/Document/979/.pdf