My PC won't turn on

[JustPassingBy]

My pc suddenly shut down on me when I was using it. Then after I turned it on, the only thing that was working is the case fan. Even the cpu fan won't work. Then after some trouble shooting I restarted my pc. Suddenly everything won't turn on anymore. The last thing that I did before everything won't work was making sure that the CPU fan was connected correctly

 

[Cycloid Torus]

"No POST" - power switch, PSU, motherboard or something else.
I like the troubleshooting advice here: https://www.computerhope.com/issues/ch000607.htm