Not sure what you mean - you mean at all? As in the main motherboard loom is disconnected at the power supply end? I have an M1-ATX and I have the motherboard loom connected but I don't currently use the "Auto ON/OFF" jumper (J6 I believe) to automatically tell the motherboard to power-up/down. Are you referring to this? ATX mboards can be fooled into working by shorting the green wire to one of the black wires (ground).