Doby

All you really need is the pwr s/w to make the computer turn on, the rest are just the lights on the tower and the reset switch, none of these are needed to make the computer pass the post test.

Try this,,,,,,, look in your manual and find the PWR on and touch these two pins with a small screw driver briefly. This should turn the computer on, it does the same as the power switch.

When you do this leave all other connections on the front panel header disconnected.

I tried to get your manual but biostars site is under construction and I was unable to do so.

I strongly recommend the bench test with minimal components because this could be a motherboard, case short, or psu problem and this will help to narrow it down