Hi, I have a Lenovo Thinkcentre M72, and have been using it with two monitors, Cintiq companion 2 (2560x1440) and HP 2159m (1920x1080) using the onboard graphic card (4600 hd). I replaced the hp with an Acer 4k monitor, so I also added a GTX 1050 2GB lowprofile graphic card. Everything works fine, except that occasionally the Acer 4k monitor's screen completely goes black (like it is turned off) for one second. I changed the cables (hdmi and dp) which did not help, but changing the power cord helped a lot! but still it happens sometimes. My pc has a 280W psu. Is this because of the power supply, or something else? I should add that the other screen (Wacom tablet) works fine when the black out happens to the 4k monitor. Thanks for your help.