I guess this is the most expensive miner I ever had. Bought four of them, two with the syscooling set, two without. The two without are working without any problem.
The first one with a cooling set had a broken pump. It was replaced. And died today. The second pump lived for about a week and then started to show fissures, loosing cooling liquid and then died.

So after all, I bought two new pumps with a shop in Europe, lost money not only by losing time for mining, but also by replacing the pumps.