Computer keeps giving warning sound and doesn't display a signal

I just built my first computer but it won't display a signal. It turns on, and all the parts appear to be working, but it won't put out a signal to my monitor. I've had the parts since christmas but I didn't get the CPU/APU until today and when I fully put it together it wouldn't display a signal. When I got most of the parts in December I put them together and turned it on without the CPU to see if the parts were working, would this affect anything at all?


Specs:
AMD Athlon 5370 CPU
Asus R7240 2gb Graphics card
AM1 motherboard
12gb ddr3 ram
an old 500gb hard drive from my old computer
a new 320gb hard drive Caviar Blue
EVGA 430 watt power supply