Firstly I cleaned my Pc, changed monitors hdmi cables.Then updated drivers.Then i took out the gpu and put it back and nothing helped.I sent my pc to a service to check it out, and after 2 weeks of testing they replaced the cpu, cpu fan and added an extra fan.Previously the problem came up every time i tried to load a game.Now it is much rarer for example today we played rust, and company of heroes and there were no problems, then after an hour of not playing i launched rust again and when starting to load the server in it said no hdmi signal again.Then I tested the system myself with 3dmark and there were no problems.I really don't understand what is happening.