Why can't I take a screen shot?

[uffestar]

All searching on this say you can take screen shot by pressing volume+power. However on my 930 this only produces a shut-down. Even tried an app for it, but with the same result.
Anything I need to enable to make it work?
Ulf

 

[dKp1977]

You need to press volume up and power simultaneously for just a short time.

 

[uffestar]

Thanks. That did it...