don't wast your money . . . theres a problem with your adapter.
Where? . . . no idea. The PowerGood is a signal thet "tell" to the mobo that the lines are stabilized and then, the power is delivered to the devices.
Are you powerON the ATX PSU from its PowerON line? or have you shorted the PowerON with the GND and you switch the rear AC button?
This is a wrong way to powerON an ATX PSU.
Take the AC switch always ON and powerON the system, trough the PowerON>GND wires via a switch.