problems with the screen are usually related to one of three causes: the graphics card, the lcd itself, or the lcd cable, connecting the lcd to the motherboard. First step would be to see if you can get an image via an external monitor. If you do, the graphics card is ruled out (if you don’t, it’s the card). Distinguishing between lcd and cable is harder to do.
Before you replace a fan, you should be sure the problem is related to that. Check and log the temps with smt like cputemp, update your bios, check for bad connections between battery and mobo, dc jack and mobo, etc. Did you clean the radiator when you replaced the fan?
I'm also wondering whether V1.1 is compatible with older versions. Still no one tried? I get asked very often to repair Surface Pro 3 with broken screen and I always refuse them, but perhaps needlessly?
There are a few steps you can take: 1) TCP/IP reset, see here: http://www.thewindowsclub.com/reset-tcp-ip-internet-protocol 2) In case nr. 1 doesn't solve your problem: reinstall Windows 3) if a clean install doesn't solve the problem, you have malfunctioning hardware. In that case: replace wifi card (should be cheap and easy).