My mac book screen is fuzzy grey with random lines running through it, whats wrong and how tonfix?

That Mac uses main memory as display memory, but its memory is soldered to the mainboard. There is nothing that can be changed by the user to get different results. You will need to seek service.

Your appointment for an evaluation at an Apple-owned store is free, in warranty or out. Apple-Authorized Server Providers may have a modest evaluation fee to keep you from using their resources without a good reason.

There are more than 100 different computers called MacBook Pro released over many years. Internally, their graphics setups are quite different. Some are using Main memory for display data, other have a private display memory.

What model do you have by year, early mid late, screen size and processor speed or MacBook Pro 6,2 designation?

I had this error too on my iMac, white border and fuzzy lines. To fix it I had to re-install the operating system - saw the tip on another thread. (reboot, press cmd-r at the startup sound, then click 'reinstall macOS'). Fixed the issue.