I solved the issue with my Surface Studio and now realize that I should have shared my findings sooner. It turned out that a connector was loose. To find this, I opened the computer on the bottom, following the iFixit video (starts at 0:29), removed the midframe, fans, SSD, heatsink, HDD and power supply and verified if the connectors from the screen to the main board were properly fitted. This seemed to be the case, but I disconnected and connected again to be sure. Then I removed the plastic cover on the backside of the screen to verify the connections on the other end of the cable. After carefully removing the plastic (2:22 in the video), I was able to locate the connectors and it looked that one of them was not properly attached any more. After disconnecting and reconnecting all connectors, the screen worked again. Please note that I did not open the display and I did not remove the zero-gravity hinge! My Surface has been working flawlessly since then. I hope this helps!