Computer Power Problem

I have a 4 year old p5w dh motherboard. I am having a startup problem. When I switch power on computer seems to get no power. No case fans, No cpu fan, nothing. The only indication of power is that the green light on the MB comes on. I have tried clearing cmos. I have tried shorting the power switch pins. I have tried reseating cpu and cpu fan. No luck. I do have a PSU tester (antec digital one) and it appears the PSU is ok. It reads accurate voltages, etc.. When I hookup the mainboard power block to the tester the PSU fan starts up and lights turn on as normal. Do you have any advice as to what may be causing my symptoms? I have unplugged everything from MB and still no luck. Is my Mobo fried? Is it possible my psu is toast yet still seems to work via tester? Any advice would be much appreciated....

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  1. I have a SliverStone 1000W PSU that worked but every other day or so I had to go BIOS and readjust my OC. It is just under 2 yrs old. It also checked good with my PSU tester.

    I sent it back for repair and they replaced it with a brand new PSU. They did not say what was wrong with it but I suspect too much ripple or voltages varying too much.

    Either way the 750W PSU I used as a temporary replacement worked fine with out needing any further adjustments after my OC was dialed in.

    That may or may not be your problem but the best way to find out would be to just try another PSU if you happen to have one or could borrow one for that purpose.

    Good luck.:)
  2. I just tried one other test. I plugged PSU into 24 pin mb plug and 4 pin cpu plug. I then plugged in dvd-rom by way of 4-pin connector. Turned power power to dvd-rom even. I then plugged PSU 24-pin to tester so that PSU fires up, dvd-rom now worked. It is seeming more and more its a Mobo thing. Only other consideration is if voltage or amperage being output by psu is corrupt so Mobo is not allowing psu to fire up? If I remember correctly, pin 14 tells psu to power up if all conditions for power to mobo and o0ther mobo functions are correct ?

  3. Well it sounds like you have narrowed it down fairly well to it probably being a M/BD.

    My PSU would pass every test I could throw at it except a 24/7 OC that I had been running for a long time trouble free. Wish I had an oscilloscope and load tester.

    All I really know about pin 14 is it is -12V. So I'll pass on that.:)
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