I have a Lenovo Yoga Pro 3 running Windows. It's done this for a while; after not using it for at least a few hours the back light will come on but the screen will stay black. In the past, pressing the power button to turn it off, waiting a few seconds and pressing the power button again has resolved the issue but now that doesn't always work. I'm not sure how to resolve this so any help would be appreciated.
Turn the laptop off (not sleep or hibernate but off).
Connect an external monitor to the laptop.
Turn on the external monitor.
Turn on the laptop.
NOTE: You may have to press an "external monitor" button. Could be the f4 button or a button with two monitors on it, for the external monitor to work.
If you can see fine on the external monitor, then your attached display, or the ribbon cable that connects it, are your problem.
If you can't see on the external monitor at all, or the problem occurs on the external monitor as well, then it is probably the graphics card/GPU that is the problem, which may require the motherboard be replaced.
You may also want to try hitting CTRL + SHIFT + WIN + B to try and reset your graphics driver as another possible fix.