Hi rebhana,
fortunately I can confirm that now - all is well, thank you! Phone is now back online after an hour or so. The screen must have turned off as part of power saving, and the phone was too busy with extraction that it didn't want to turn it on in either way (touching the screen, the slider at the right side, etc).

If that's OK, I'll leave the original question + answer here, hoping that it gets indexed for anybody who might encounter the problem. Somebody might also want to put that in the installation notes ;-)