My PC won't turn on can't find out why

[ironfist26512]

Hi.My PC had some issuses like this during these 2 weeks. When this happened first for me I just simply solved it by unpluging everything (monitor, speakers and case itself) for a while around 2 to 3 hours and again pluging them. It happened 2 more times and it worked both other times. But when it happened for the third time it didn't work. I unpluged it for over 12 hours But it didn't help. The light on the motherboard is on but it won't turn on. I also tried shorting both PWR BTN pins but it didn't work too. Please help.

 

[Barty1884]

Please post your full system spec.

 

[ironfist26512]

Motherboard : ASUS M4N78-AM
Graphic Card : Nvidia Geforce gt 1040
Cpu : AMD Athlon 2.4 Ghz
RAM : 1 GB
V RAM : 1 GB