Black screen after using boot camp assistant for windows 10

iMac (Retina 5K, 27-inch, Late 2015)

I have wiped my drive and created a fresh install of macOS. I downloaded the latest Windows 10 iso and used boot camp assistant to install. My Mac automatically restarted but after the Apple logo, the screen turned off (no backlight). Restarting using the power button while holding alt to boot from the windows partition has the same result.