I have for this setup a 240W power adapter. I have thought that bigger is better, but it might actually be one of the reasons the problem is so severe.
I noticed that the problem is triggered, when the CPU starts to work. As I wrote in a earlier post, the problem is connected to doing something graphic intensive, like watching a video.
I was questioning someone from work what kind of power supply we usually deliver whit the D6000 dock, and that is 130W. Just for the test of it I replaced the 240W with a 130W, and that resulted in a big improvement. I still have the problem, but maybe only 1 out of 10 times, compared to before the switch....
That was strange.... Doing some more tests.
---- Edit after a week.
This did NOT fix the problem....