HDMI no signal or display on monitor

Hello,
I just recently got upgrades consisting a 4690k processor, gtx 970 graphics card, b85m matx board, and 32 GB of 1600Mhz ram. After the dude who installed all this for me tested it at his place everything worked fine. I take it home and connect all the right cables to their proper places, but when I turn my rig on my monitor displays a HDMI signal failure message then will shut down for power supply. I have tried some tricks, like disconnecting power cord and holding On button for a minute, cleaning up dust particles and reinstalling RAM, ect... I do not get the green light so keyboard works. Any new easy to follow suggestions to help? I'm a newbie to the computer world, and haven't built a PC on my own yet, hence why I didn't install the upgrades myself.