Question Motherboard booting directly from PSU

[XMEN_2012]

Hello,

As you can see subject line I have AsRock Fatal1ty AB350 Gaming K4 Motherboard and due to some fault it is booting itself while I turn off PSU switch without taking any feedback from cabinet power button or Motherboard jumpers. It is quite unused due to this my Graphics card is not showing any screen but works fine with other board so no problem with Graphics card. What could be the issue? I believe its I/O chip is gone but can't be sure.

 

[CountMike]

That doesn't make sense, how could it boot when power is switched OFF ? It can only boot when it's turned ON. No power, no boot or anything working !
It's possible it can turn on and stat boot process when power is applied and without touching Start button. Ther should be a setting in the BIOS to prevent that, usually worded something like " Restart on power on or after power loss".

 

[SkyNetRising]

Dead motherboard can behave this way.