Computer shutting down and starting up by itself
I have a weird problem. One of my PCs sometimes won't start when I press the button (there is power to the motherboard; I can see the little green light on it) but then after a few minutes it springs to life. Other times, it will start but then stop by itself, then restart some time later. I don't think it's temperature-related.
I'm thinking power supply or motherboard, maybe RAM, but before I start on a "change this change that" maintenance task (can't even MEL this one!) I would be grateful for any ideas from the floor.
Thanks!