I am sorry to say this James, and others can chime in here if they disagree, but I'm pretty sure that screen is dead.
There's a chance it is a connection issue. Did you try reseating the cables? But if not, it is likely a separation issue where the screen was pulled apart and the layers through which the data connection flows were separated at some point.
It is not exactly your fault, Microsoft has made these things as hard to service as possible (they earned the lowest possible repairability score for a reason), and no matter how careful you are screen issues have been known to happen on Surface devices.
Был ли этот ответ полезен?