When you say you checked the fuse did you just look at it assume it was o.k. and put it back in or try another one? Visual inspection only is not always the answer as that sure seems like the problem as double power supply failure at the same time is highly unlikely.
In my email to Nord I made special reference to let it be known that I used a meter. I agree with the unlikelyness of double PSU failure which is just additional indication that a total lack of thought and concern was provided to me.