Your MacBook Pro using Windows 10 is interpreting an external monitor as connected.
Your MacBook Pro using Windows 10 is interpreting an external monitor as connected.
It doesn't work the same on MacOS Sierra—your HDMI connection needs some tweaking (you might need to adjust the plug). On Windows 10 it interprets an external display as connected, which can cause issues like a black screen when booting. You can try disabling the built-in monitor in Windows settings if the HDMI issue persists. This should help avoid the problem without needing to replace your MacBook.
my mac lacks standard keyboard keys found on windows laptops. consider connecting it to an external monitor, enabling screen mirroring, turning the external device off in settings, and restarting without using a display.