The A3000T motherboard has an ATX- type connector BUT IT'S NOT COMPATIBLE WITH MODERN ATX POWER SUPPLIES, the pinout differs.
I built my own adapter for my lone 3000T motherboard (see the thread
here) with a regulator for the missing -5V line. Not an easy build, though.
Regarding your other threads about the 3000T of yours, the keylock is not required to boot. It has key+mouse lock and reset but you don't need to have those connected for booting.
