Yesterday I have changed my ups battery due to a fault. After powering up my nMP (6core - 2x D700 GPU) it showed a strange flickering effect on the bottom of the monitor (Asus PB278Q via hdmi) and than something like (it's not the real image, I have found it on the net for example and show): After powering it off and on again and after an apple hardware test no more problem at all. The nMP has worked like a charm without problem for months. And now is working very fine in all the application I use (FCPX, DaVinci, LR, Photoshop, Modo). Have to be alarmed about? A GPU fault? The nMP is covered by apple GPU program (although I never had a GPU hang problem at all) and it also covered by warranty until June 2018.