Why has my Lumia with Denim gotten a black screen?

[Windows Central Question]

Why is my lumia denim went blank screen?

Well, not really blank. nothing appears there's no picture, I can't see any of my apps but it vibrates and has a sound and I can also receive or answer calls by just sliding it up and pressing the left side of the phone --- seeing nothing....
Pls. Help me....thank you...

 

[Ed Boland]

Re: Why is my lumia denim went blank screen?

Have you tried restarting the phone? Hold down the power and volume buttons together for about 10 seconds until it vibrates.

If that doesn't fix it, you may need to use the recovery tool on your PC.