long story short; motherboard fried so i built a new computer using some of the old parts plus a few new ones

the old mobo was an 1150 intel so i decided to just upgrade to the next generation of amd boards and try them out. So, I put the computer together and:
>no signal out my gpu
>took that out
>no signal out the mobo hdmi
>no signal out the mobo dvi
>computer clearly turns on, fans turn, mobo lights up
>tried two different monitors
>pretty sure everything is seated and plugged in correctly
wtf guys what is going on here? Im an utter newfag when it comes to this, and ive been without a decent computer for weeks now so help is greatly appreciated.

note: I did not reformat the old HDD I re-used I figured that the computer would make me do that anyway when i booted it up, which is what has happened to me in the past