No signal to monitor, keyboard or mouse

So I fully upgraded my pc the only old parts are my CPU, graphics card and hard drive. I made sure everything was compatible and plugged in in the right places. When the pc turn on my mouse lights up for a second and the monitor just says no signal instead of not connected. I've tried removing the battery (that is brand new) still nothing. Does anyone have a fix?
I was struggling with this in my new build. My solution was to plug in an old monitor into the graphics card. At first I was using a brand new HDMI monitor and it just wasn't responding until I had graphics card drivers installed.
Hopefully this is your issue too so you'll be spared diagnostic hell. best of luck.

Oh also with newer monitors, sometimes you need to hit buttons on them to make them refresh and recognize hardware, so (if this was your issue) keep that in mind for later.