Weird cpu debug led and screen behavior

[idk2]

So I finished building my first pc but theres a possibly big problem. The debug lamp of the cpu blinks in a wierd pattern (two times, although it should glow permanantly as long as a problem exists), stops after 20 sec and blinks a millisecond when I turn the pc off. 

Meanwhile the screen says: No Signal but if i unplug it slightly and plug it back in or press the plug even more into the port it seems to get a very short signal because it sometimes shows the message "No Signal - Please check your connection" 

Does any body know what i could do to make everything work? Many thanks in advance.

 

mainboard: msi b350 pc mate

cpu: ryzen 1700x

ram: crucial ballistix sport lt gray ddr4 2400

gpu: gtx 1070 zotac

psu: 500W be quiet! pure power 10

 

Tell, if there is any more information needed.I'll respond as early as i can. 

[0x1e]

1 hour ago, idk2 said:

 

My best bet would be  that you have a loose / bad power connection somewhere. As you said, the light should not blink.

[idk2]

8 hours ago, 0x1e said:

My best bet would be  that you have a loose / bad power connection somewhere. As you said, the light should not blink.

I think you're right! The atx  power cable has not clicked into  place yet.  

 

Edit: Nevermind, I can't push the cable further into the port.

[idk2]

8 hours ago, 0x1e said:

My best bet would be  that you have a loose / bad power connection somewhere. As you said, the light should not blink.

I checked every cable but no cable seems to be loosly plugged in.

[idk2]

I pluged the atx power cable out and back in and suddenly the second blink isn't from the cpu debug ledanymore but it's from the gpu debug led and the gpu ran for a few seconds and stopped after a restart

 

Edit: I restarted the pc and replugged the dvi cable  a few times  and and the  gpu did't stop but the led still bliked.

Edit2: The gpu fans work fine agian but the led pattern is still the same.