I just put a rig together for my son and shipped it to him. It was working perfectly. Asrock X399 Fatal1ty Pro Gaming, EVGA 2180 Tix2 with nvlink. When he got it, it power up fine. However, the nvlink was completely disconnected, and only one video card is working. When the nvlink was reattached, it was unchanged. Upon startup, the card lights up for maybe 10 seconds and then goes dark. The card is not seen in device manager. Removing and reinstalling the nvidia driver did not help. Any thoughts?