IdeaPad 330S - black screen on boot after firmware update

Had a message pop up telling me to restart my IdeaPad 330S to complete a Lenovo firmware update. Tried this, but the update wouldn't install, and had the same message pop up again on desktop.

Went to Device Manager, and attempted to individually update drivers (as per a suggestion on another forum). One firmware driver found an update, downloaded it and said I needed to restart the laptop to complete installation.

I restarted, and the Lenovo loading screen came up with the timer and a message about installing. The timer/message/Lenovo load screen froze. I left it for 2+ hours, still frozen. Eventually gave up, and held down the power button to turn off.

Pressed the power button again, hoping for the Lenovo loading screen to appear. Instead, just a black screen with the power on. Now nothing loads, it's just stuck on a black screen whenever I power on.

What happened? How can I fix this? Thanks.