Monitor won't work for my first time built PC

So today I finished building my first PC and when I try to boot it the monitor just won't work the 'no signal' sign dissapears but the monitor just won't turn on. I'm using a few components from my old PC like GPU and the Said monitor aswell as RAM so I'm sure it should work fine.

Any help would be appreciated.

Go ahead and list the specs of the PC.

It might need a CMOS reset if its a RAM issue. Make sure everything is seated properly in its slot. Try booting with a single stick of RAM if you have multiple DIMMs.

Check for these power cables:

4 or 8 pin CPU

24 Pin motherboard cable

6/8 Pin + 6/8 Pin GPU cable. 

DVI or HDMI or VGA or Display Port is plugged into the graphics card and not the motherboard

My specs:

Gigabyte 970A-DS3P

AMD FX 6300

Radon HD 6670 1gb

2X 2gb RAM 

Tried booting with only one RAM but that didnt work im gonna check out those power cables again but I was pretty careful with connecting pretty much everything. Any other suggestions if the power cables arent the issue?

What happens with the computer when you try to power it on?

Do fans spin?  Does it try to reboot itself?  The more info the better.