Desktop don't turn on, motherboard lights up

[Elmoo]

I have checked the plugs, power sockets and my desktop just won't turn on. Motherboard's green light is on though. The desktop is bought about half a year ago and I didn't screw open anything inside. This morning it is acting fine but then when I tried to turn it on in the afternoon, it just didn't respond. The photo is the back of my desktop.

 

[Cycloid Torus]

No flash screen on start? Fans spin? Bought new 6 months ago? Likely to be a warranty issue...look up your deal with the vendor and go back to him.

 

[Elmoo]

No flash screen on start? Fans spin? Bought new 6 months ago? Likely to be a warranty issue...look up your deal with the vendor and go back to him.

The monitor says "no signal", and there doesn't seem to have any electricity going through the system unit (except there's light on the motherboard). No fans, nothing. I can't find my warranty sticker on the system unit Is there a way to fix it myself hopefully without opening the system unit? I'm not really a pro in fixing pc.. thanks

 

[Cycloid Torus]

If it isn't a loose plug, then you need help. Locate the record of purchase and go to vendor with that information.