CX430 causes no boot after a shutdown

I have a CX430 power supply, model 75-001666. I've verified that it is defective by replacing it with another power supply. But before I send it in as a RMA, I'd like to see if there's a fix I can do to save return shipping cost.



I power off my PC every night when I go to sleep. When I do a power on boot in the morning, my PC displays the BIOS splash screen and then boots normally into Win7. Everything works fine as long as I keep the PC powered on.



If I do a restart from Win7, the BIOS splash screen displays and the restart boots back into Win7 fine and everything works fine.



But if I do a shutdown, wait 5 seconds and then press the power button on my tower, the boot hangs with the PC's power led on but nothing else happens. No BIOS splash screen and the numeric lock led on the keyboard does not go on. It looks like the boot is hanging before any POST happens. If I hold the power button in until the PC powers off and then try to power on boot, the same hang happens. ..... However if I wait 10 minutes and then press the power on button, then the power on boot will display the BIOS splash screen and boot normally into Win7. These symptoms are repeatable.



My guess is that the CX430 is not sending the "Power OK" signal to the motherboard after it is turned off by a shutdown. After waiting 10 minutes, some voltage bleeds off and then the "Power OK" signal starts working again. But this is just a guess.



Anyone know if there's a way to fix this problem without having to return the CX430 for a RMA?



Thanks,

Skyzoomer