PSU :Seasonic 400 Fanless
If I unplug computer from wall outlet for a day+ I experience the following problem:
1) when I plug PSU on, mobo is still off. but LED2 (attached image) is turned on, and board does not boot when pressing power button. (normally this LED should not be on when motherboard off)
2) turning off/on PSU switch for a second fixes this. also can be fixed by holding power button for 5 seconds.
seems I experience this problem from the day I bought the board.