MacBook Pro Blackscreen after Bootcamp Installation

"When I hear in the same sentence Macbook Pro i7 and black screen my mind goes straight to fried discrete Gpu, but I hope this is not the case.

Drivers get loaded during booting process, do not just get stuck into the Gpu, thus the bad driver idea can probably be discarded for good.

Try booting keeping the Alt key pressed..that should take you to the window listing boot partitions available. If you get your screen back it's probably just a software issue.

In case the screen stays black try shining a strong light to the screen and try to see if you got an image but no backlight. In case it's not a backlight issue try opening the mac and with care and battery disconnected try reseating the Lcd connector and check if you see signs of burns on connector or logic board. If none of these change the situation try reporting back, hopefully someone's got further ideas but I would vote for a dead Gpu in that case."

"For my MBPR 2012 just connect a secondary screen with HDMI and Windows 10 is there on the secondary screen. Then >> Setting->Display->Change brightness for the built-in display (higher)

Then the built-in display is working now"