Compter not powering on, motherboard problem

Hi,

Ive always had a problem turning my computer on so usually i never turn it off, just put it to sleep. The mains was switched off for a while for some house work. Now my comp just wont turn on. I got the green light at the back and orange light on the mother board. I know its not the power supply as i can hear it doing something when i plug it in but fans not on. Ive also bought a new on/off button but this didnt help either. Please can someone help out?

Please help.

I didn't find the right solution from the Internet.

References:-
https://bit.ly/2rx7YVR
Explainer Video Production studio

Thanks