Z390 AORUS PRO - AC Back bios function

[pfolzini]

Hello everyone, I'm working on a build with Z390 AORUS PRO and a Corsair TX750M power supply. I have the need, to test components, to switch off completely the Power Supply several times (with the back IO button).
Then, everytime I switch ON the back button, the PC has a short start, to stop immediately, after a few seconds. A lot of PCs do that, but this one comes out with a Samsung SSD 970 PRO M.2 NVMe and everytime there's a "power loss", diagnostic softwares (for example HD Sentinel) mark the short start as an "incorrect power loss".
I've found in bios settings AC Back function and the only way to avoid "incorrect power loss" increasement is to set ALWAYS ON.
So I turn off the PC, turn off Power back button (to 0), change a component, and when I switch on Power back button (to 1), the computer has a complete and regular start.
My question is: is it possible to switch on the back power button without any automatic start of the PC?
Thanx a lot for any help

[shadowsports]

Greetings,
I have 2 Z390 boards.  See my sig, One is 16GB RTX2070, one 32GB RTX2080.  Tx850M's. Primary storage on both are 960 Pro's.  Both are running F10 BIOS.  So essentially the same as you from a base component standpoint.

I have AC Back Up set to off, which means the system remains off after a power failure.  I have both machines on UPS, so there is never a system failure even if there is a power outage or interruption. 

I am not completely clear what your "need' is or what you are trying to accomplish.  HD Sentinel usually runs in the background on an installed OS and cannot monitor, log or track events unless the OS is running.  so when the system is off or hasn't booted, it does not operate.  Maybe you have a different configuration and can describe.

In regards to your last question.  I am able to turn the switch on the PSU on/off with no  problems.  The systems does not "start" or boot until the power button on the case is pressed.

I think more information would help me understand what you are trying to do or accomplish.

[pfolzini]

Thanx for your answer.
Actually my problem is that Z390 AORUS PRO mb has this strange "check" and then turn off without any boot. It seems to be not an issue.... I've to google a bit
HD Sentinel simply says that the M.2 has been on for a while and then stopped unsafely (the strange check is seen like a boot).
I simply want to turn on the back supply button without any event.
Thanx again

[pfolzini]

It was the power supply. I tried a Cooler Master 550W (low cost) and the "short" boot disappear. I've got 2 Corsair TX750M. One is Ok, the other has this issue common in this model (google told me). Corsair as well Enermax get worse every year
I'm going to buy this:
https://www.amazon.it/Antec-EA650G-alimentatore-computer-Nero/dp/B0773MCJGB
Thanx again for your help
peace

[pfolzini]

I made a mistake. It was not the power supply. It seems to be a power check of the board.
I've asked few hours ago to Gigabyte esupport.
I'll keep updated about their answer