New build keeps saying check signal cable PLEASE HELP !!!

[Saint]

So my old machine was not working because it would keep saying check signal cable but would boot up and power fine. I tried everything with it and it would not work. I plugged in an old gateway into the same monitor and cables and it works fine. I replaced the video card, motherboard, and power supply on it and it still didn't work. Now I built an entirely new machine of all new parts and I am getting the same stupid message "no signal is coming from your computer check signal cable. The system powers up fine but it does not make any beeping sounds. What the heck am I am doing wrong. I am about to jump off a bridge.

 

[Dangman]

Check the stickied "Basic Troubleshooting Guide" on what to do when your system does not POST.

 

[engiNURD]

does the new system work with another monitor?