A most perplexing problem occurred with my Windows Server computer. This computer was built about 2 years ago and is my primary server for the home network. It has a SuperMicro Workstation Class motherboard with ECC RAM. I built this box, after getting annoyed with inexpensive Dell Tower Servers. The Dell Servers performed well and are a good deal for most people, but my server is in my home office and I prefer a quieter box. The Dell Servers have noisy fans and even trying a few different replacement aftermarket fans, they still produced enough noise for me to invest in a custom system. I also found myself replacing the Dell Servers more often than I cared to. They were cheap enough, that I would end up upgrading the entire box every two years. The server I ended up building was very quiet and ran 24/7. It was connected to an APC UPS and so it ran almost without interruption. At least it did this until rather recently.
After running for two years, the box was completely silent one day. Pressing the power button on the case would do nothing. There were no lights or any other signs of life (in this case electricity). I unplugged the computer from the UPS and into the wall outlet directly. Pressing the power button on the case would make the case fan and cpu cooler fan spin for about a second or two. The motherboard would never light up. It would only do this once. I had to unplug the power cord and try it again to get the fans to spin. I then unplugged the power supply connectors from the mother board and then tried the paper clip test with the power supply and it would power the fans again for a couple of seconds.
Alas, I could not resurrect the computer. My next step was to order a new power supply from Newegg.com and hope that it was my fancy power supply and not my fancy workstation motherboard that died. The new 1050W power supply was an upgrade from the 850W it was replacing. Other than the wattage difference, the new power supply had a switch to cycle on and off the power supply fan as needed. Once I swapped out the power supply, the box came back to life. The good thing about buying good components is that they are warrantied. I submitted an RMA request through the manufacturer website and a few days later, it was approved. After a week or so, they sent me back another power supply. I expected them to send me back a repaired unit, but instead they sent me back a brand new sealed box!
Before I sent my power supply, I inspected it without opening it. The only thing I detected was that on the top of the unit, there was a sharp indentation, where it seemed as something pushed up against metal from inside. I am pretty sure that was not there when I installed it originally. Other than that the unit looked normal.
The Windows Server has been running now normally for weeks.