I had a similar issue at one time with a PC using the onboard Intel Gfx. It worked initially but after a Windows Feature Update, the video output would disappear. I could make the image come back by going into failsafe mode, delete the driver and have it run with the MS standard video driver, however after rebooting the machine it only took around 5 minutes before Windows thought it had to install the 'proper' driver from Windows Update and then the problem came back.. I don't remember exactly how, but I managed to force it to stay with the standard Microsoft driver. Obviously the performance was horrible but at least I was not blind and this particular machine was not going to be used as a workstation anyway so the performance wasn't very relevant to me.
So my guess is that it is driver related somehow. Windows could also be trying to set a mode which is unsupported by the monitor, so try setting it to something safe like 1024x768@60 Hz (you should be able to do that in safe mode).
After you uninstalled the graphic driver, it will be replaced with the microsoft basic display adapter
, and it will decrease the quality of the image.
Besides of the graphic issue, you can try to plug your ram to another pcie slot if your display has no sign.