Screwing brought the realization that the thing should be internally functional due (mechanics), so the cause was initially only to a cable fault (break).
Only in a forum I came across the solution, the small plastic edge rests on the bare plug part, must be removed with a knife so that the plug can be inserted deep enough into the socket. Now he works.
The first pressure point is not very clean felt, but for the money I did not necessarily expect, function, however, already ...
Conclusion:
For my purpose sufficient, one should not expect too much, at least not paid more than you :-))
