I built my PC about 3 years ago. CPU Core 2 Duo 6600 @ 2.4GHz, Video – 7950 GTKO; MB – Intel DG965WH, 2Gb ram, XP Pro. Recently I noticed that PSU fans as well as the chassis fan and CPU fan would continue to impulsion run well after the machine was powered down. The only latest add-on was an external Seagate Free Agent Pro – 1TB and it was few month ago. I fully cleaned the system of dust but no change. Yesterday after shutting the machine down I found it would not start. No beeping motherboard or hard drive spinning up, etc... After unplugging and cleaning again (for nothing) I was able to get power up only to discover “Unmountable Boot Volume”. Went on the net, found MS “support.microsoft.com/kb/555302”, used original CD to repair system – as result PC boot up. Shut it down. Went to work and now I have a same picture. I got only spinning impulsion of the fans and no way to turn the PC on. If I would turn power off on the surge protector, spinning would stop, but it would continue with the power back on. At some point I was able to get to the BIOS setting and check voltage; I got +11.88, 5.22, 3.32, 1.2. Thank for the help

If you have another power supply try that one out on the same motherboard to see if that is the problem. Jim R

The ATX spec allows a 5% tolerance +/- for the voltages but some lower end PSU manufacturers stretch it to as much as 10%. Here's the acceptable ranges: +3.3v = 3.135v to 3.465v +5v = 4.75v to 5.25v +12v = 11.4v to 12.6v All your voltage rails are within spec but unfortunately, there's no easy way to check amperage. Without the proper amperage, the system won't boot. If you remember the old formula: Watts = Volts x Amps. My guess is your PSU is failing. What is the make/model/wattage?

Jam, I have GearMax, TRU600P (600W); current reading are: 12.026; 5.210;3.33;1.30 Any other ideas?