does not turn on

Hello guys , my pc turn on but no display, keyboard and mouse turn on , i checked the capslock it works , but no display , i tried to change the hdmi , still no screen , after a min , i tried to press the power button to turn it off , and it turn off within 1 sec..what should i do? Cpu intel...

Brought my computer home from a technician to fix my CPU fan error. Everything was working perfectly fine on my computer at the shop when I went there to pick it up. Was able to log in with no problem. Got home, did a quick un-build to do cable management, and plug everything back in, got power...