Hi CU_AMIGA,
. . .erm!! sorry but i haven't understood quite nothing :-)
The OLD PowerTower switch, had 4 wires . . .right?
In a AT PSU enviroment, it switch ON/OFF the 220 volts AT PSU.
Now you have an ATX PSU, right? with an ATX2AT adapter, right?
Are there 2 wires from the ATX-PSU (the PSU-ON ones), right?
So, only for testing pourpose . . . try to put togheter those 2 wires.
Ciao