I donĀ“t know.
I installed 3 different versions of Ubuntu today.
None of them were able to connect to PHD2 .
I even get more problems in kstars to get the lodestar looping...
Not even in bin 2x2 anymore.
I totally give up now.
The only explanation to me is a hardware-damage of the laptop.
I close this topic here, it makes no sense anymore. Thanks all for your help...