I have an Intell Motherboard D945GCZ (3.0 GHz Processor). My system went down while using it. There was no power jerk. Though it was raining outside the room for few days. Now I can not see my PC come alive. When I press start button on front panel I see that the System LED becomes green and the Hard Disk red LED comes for a moment (less than a second) and goes down. I have checked the initial +5 volt on the purple wire on the ATX. It is ok. I have then checked the green wire voltage it gives (4.3) a logic of 1. It is ok. However when I push the start button I do see the green wire voltage to from logic 1 to logic 0. But as per specification the logic zero should be less than 0.9 volt but I am getting 0.012 volt. Is this a problem. As I know this (logic 0) has to trigger the PSU to start providing the supplies. I don't get any voltages on any other yellow or blue or red lines. No Fan Spins. No Sound. I even removed all things one by one, such as harddisk, DVD, USB, Audio, Memory. Nothing happens. Is it anything to do with motherboard or PSU. In my openion power supply is ok as I replaced with by taking another from a running PC. Please Help!
To verify your PSU, remove all cables attach on your motherboard/HDD/Drive/GPU. Than on your 24 pin connector, short the green with the black and the power supply should start.
Now, verify your +12V, Yellow with black and +5V, Red with black.
If you read nothing on one of these, your PSU is faulty.
Also, if you read on your +12, 11V and less or your +5V, 4.5V or less, your PSU is also faulty, without load, the output should be the higher than normal.