My daughter's ultrabook started producing smoke and the screen failed. Teardown revealed the screen cable at the left hinge had failed with the electrical short melting the cable screening. I have replaced the cable and the screen but all I get is a white screen on which I can only adjust the brightness. The screen will black out temporarily as Windows loads. At that point, the HDMI output is activated and this still works fine so the notebook can be used with an external monitor which while useful is impractical.
I have tried a hard reset with no change. Of course it is possible that the replacement screen and/or screen cable are faulty but I have no means of testing these.
I would welcome any suggestions short of replacing the motherboard : for example is there a screen fuse on the motherboard or a physical reset button.