I was doing work when suddenly screen goes black and monitor is not off as well as cpu.. Everything is working fine. Then I tried putting my vga cable to motherboard default slot and screen reappeared. I tried almost everything..removing cmos and keeping pci e first priority in bios, uninstalled graphics card drivers.the problem is it works when I insert into default on board graphics slot but when I insert into ati radeon graphics slot it does not works. Yet graphic card fans are working as usual