Ryzen 5 1500x fail

Hi, I have got an amd ryzen 5 1500x and a msi b350 gaming pro motherboard. When I first started the pc the cpu debug led has turned on. I haven't seen the bios or any thing on the screen. I have removed the cpu and installed it again but same thing happened. In the motherboard manual it says that the cpu debug led means that the cpu is not detected or failed. I don't know what the problem is. Please help.