A little feedback on my issue:
So far, nothing that I have change on BIOS or OS is working. Even Cleared CMOS, but still the same. Reboot and not shutdown.
What is confusing me is the fact that everytime I trigger the Emergency shutdown, the Aquaero spins the fans at 100%, as I have set in the options. If I reboot the system with the case button or by SO, the fans do not spin up (they never did).
That is making me think that the Emergency shutdown does, indeed, shutdown the PSU and the Aquaero recognises the power cycle. Which leaves me with a Mobo that doesn't want to stay powered off that way no matter what the options in BIOS say.
I'm running out of spare time to troubleshooting this, so, will the following diagram work? Theoretically, at least.
Do the power switch wires need to be connected like the red wire or like the green wire in the image that I've attached?
Thanks for your time.