Monitor shows "no video input" and then enters sleep mode

[UmiRyuu]

I just bought a new pc and connected all the cables then turned it on. Then on my monitor it said no video input and then it just enetered sleep mode. The first time I got it id said the same and I sent it back for repairs. It's still not fixed after I got it today. It's connected by vga cable. What is the problem then?

 

[Cycloid Torus]

"New" - contact your vendor after checking proper connection of monitor to video output.

 

[MaikuTech]

Open the case up and see if you have a video card, turn the case around and check and see if you have onboard gpu.
Turn it back on with no video card connected and make sure the onboard gpu will go to the bios post screen, then onto windows.

https://www.wikihow.com/Change-a-Graphics-Card