For about a week, my desktop has been acting weirdly.
Sometimes, after pressing the power button, it turns on instantly.
Sometimes it does not react at all. No sounds, no lights, nothing beyond the click of the power button. (The button's okay, I can test that much.) Disconnecting the power completely for several minutes sort of helps.
Sometimes it does nothing for maybe a minute, then suddenly springs into life just when I'm about to walk away. Again, in the meantime it remains completely dead.
This happens regardless of whether the computer was connected to the power source right now, or had been connected for the entire night... It's just random from what I can see.
The PSU appears to be working, though: the motherboard light is on, as well as the Ethernet lights. Unfortunately, I don't have a second compatible PSU to test with... Is it time for a replacement, though?
What makes this more interesting is that the exact same behavior has been reported to happen with several computers at a nearby school in the city.
Any ideas what could be causing this?