Nobody can help you with such minimal information. Your monitor just went black after it started flickering? Were you doing a BIOS update or a Windows update or just gaming? Tell us about what's in your system.
One thing to try is swapping out a few cables, such as the monitor to video card cable. Maybe your video card is a bit loose; try to remove and reinstall it in the same PCIe socket. How hot is your system getting? Are you monitoring the temperatures of the CPU / Video Card / Chipset?
As Albert Einstein said, "I could have done so much more with a Big Al's Computer!".
