Question why does my monitor say no signal

[Brendanm504]

i just built a new pc and everything inside the pc spins and turns on however when i plug my monitor in from my graphics card it says no signal. i have a msi b450 tomahawk mother board and some lights flash for a short bit but go away. i don’t know if this means something or not. can anyone please help me figure out the problem

 

[rgd1101]

full system spec? include make and model of the psu

 

[Brendanm504]

psu is a corsair cx550. gpu is an msi radeon rx 580 armor. cpu is an AMD ryzen 5 2600. 16gb of ddr4 corsair veangance. and 1 tb hard drive