Touchscreen works, but display is dark. Can I fix it?

After the phone fell from my pocket onto a tile floor, the display went black. For a while I could see a few thin, faint horizontal lines at the bottom of the display, but then those went dark, too.

The touchscreen still works. I can answer calls (if I swipe in the right part of the screen), take pictures (if I can hit the camera icon blind), and so on.

I used the disassembly guide to locate the display data cable. I pried it off gently, then snapped it back on and reassembled the phone, but no dice - it acts exactly the same. What else could be the problem? Is it fixable?