Had my PC for about 4-5 years IIRC. Not a problem to this day.
Happily using it as normal when it completely turned off randomly. No loss of power/electric in the house. Left it for awhile, pressed the power button and zip, nada. Not even a motor starting.
I have an external harddrive, connects VIA USB and that seems to remain connected and I get a blue power light on my case when I press the button, so I think my mobo is OK (not sure if that's a fair conclusion). Never had a prob (or replaced) the psu over the 4-5 years, so might it have just given in? It's a 550w, i have a 9800gt but I think 550w is fine for that, right? Mobo is pretty old (ddr2, eep) but I'm not sure if the signs I've given indicate it would be fine.
If you need any more info to help, let me know. And thanks in advance.
guess if could be your PSU... but it also can be your Mobo too, just totally fried.
but before you rush into things, you can try looking at your power strip and see if everything is okay there... i honestly wouldnt know how you would troubleshoot a PSU... i guess if you have an old one you can try plugging that one in and see if that one works? but if not then idk. cross your finger that nothing happened to the actually MOBO!