My computer (an HP TouchSmart tx2 running Windows 7) just randomly shut itself off about 30 minutes ago and won't turn back on. I had heard that there were heat issues with this particular make, and had had heat issues with it in the past, but I don't think that's the case this time as it wasn't running very hot. I also don't believe that it's a PSU issue, as I've plugged the PSU into other computers without problem.
I wasn't doing anything too strenuous on this particular PC; in fact I had just (about four days ago) migrated a bunch of music and stuff to an external hard drive and freed up a significant chunk of space. All I had done was open up Firefox's usual 2 or 3 tabs, which generally even the oldest computer has no issue running.
I'm not entirely sure of the specs with everything "under the hood" (so to speak), but I believe everything is still from the factory (I've had this computer since December 2009).
Update: I tried the following:
1.) Unplug everything and remove battery (laptop battery, not CMOS).
2.) Hold power switch in "ON" position for approximately 30 seconds.
3.) Plug PSU back in.
4.) Turn on PC.
5.) Put battery back in.
The first time I did it, everything came back on, and then (like an idiot) I put the battery back in, and was back at square 1. Repeating those five steps warrants nothing - only a flicker of the power indicator light (for literally a quarter of a second) without the battery in the unit, and with the battery in, I get nothing.
Could a bad battery have caused the entire system to nose-dive like this, even if it was running off of AC power the whole time?