Can't get build to display

[CSP88]

I just got my PC put together, and I tried hooking it up and powering it on. However, it would not display on either of the monitors that I was using. To be more specific, I am using a 32-inch HDTV and an old monitor that only has a VGA connection. I hooked up my PC to a VGA cable through the motherboard on both screens and nothing worked. I also tried using an HDMI cable connected through my graphics card to my TV, and that didn't work either.

I should mention that I was able to get my PC to display last night through the VGA connection on both screens. However, I only had my motherboard and PSU installed in my case. Also, I have tried a few runs on a basic external build before I put everything in my case. I never got it to display when I had the GPU plugged in, but it worked when it was just the motherboard and PSU. Is there a problem with any of the components, or am I just using the wrong connection?

 

[a little black duck]

.... I hooked up my PC to a VGA cable through the motherboard on both screens and nothing worked.......I never got it to display when I had the GPU plugged in, but it worked when it was just the motherboard and PSU......

When you add a gpu, the motherboards onboard graphics are disabled. So, any and all monitors will need to be connected to the gpus' monitor I/O's.

 

[CSP88]

^I figured as much. As for the rest of my problem, I actually figured out what was wrong, and I feel really stupid for it. Turns out, the HDMI cable worked but I had to set my TV to the HDMI setting instead of the PC setting I had it at when I used the VGA cable. I'm just going to chalk this up to first-time builder nervousness and hope that my next question here won't be something that I can figure out myself.