Hi every one. My girlfriend's computer is doing something I've never seen a computer do. When I turn it on, it comes on for a few seconds, and then immediately turns off. When you're lucky, the splash screen will appear for a split second before turning off. I've tried tapping F8, F2 and DELETE, trying to get into some menu--any menu--before it turns off again, but it never does. Then, after it's been off for a second or two, it automatically comes back on, and does the same exact thing. If you don't unplug it, it'll just keep turning off and turning on, over and over again. I've been digging around online and can't find any reason as to why this might be happening. Any ideas?

Time to give Memory Dump a call. Or are you comfortable opening the side cover & going inside the PC?

And don't forget to try Hair Now 3000! http://www.youtube.com/watch?v=UbmU... But before doing that (or calling Memory Dump), open the case & have a look to see if the CPU cooling fan is still working. Also check for dust accumulation on the fan blades & heatsink.

This sounds like a heat or voltage (PSU) problem and that the system is protecting your hardware by shutting it down. As this happends fairly quickly, first check that the processors big cooling heatsink is securely fixed in place. Bad fans and dust will also get the PC to missbehave but that takes a while in windows before problems appears. Power supply is more difficult to check but confirm that it's internal fan is spinning.

Thanks for the suggestions, every one. I've opened up the side, and the fan is working fine. There was a fair amount of dust, but I don't have any compressed air, and wasn't sure whether I should brush it with anything. I figured it'd be best if I were to wait until I had some compressed air. I'm not convinced, yet, that the dust is the reason this is happening. I've seen other computers that were far dustier, and were still working fine. It really just seems like a normal amount of dust. I'm also fairly sure that this isn't a temperature issue. First, the computer runs for just a few seconds before shutting off. Second, the CPU fan is still working. I've had computers that turn off due to overheating, and they've always taken far longer than a few seconds to turn off. The possibility of a voltage issue sounds most plausible to me, but I don't have a lot of experience with these things. So, if you guys feel that this is likely not a dust/overheating issue, how might I check whether it's a voltage issue? I'm comfortable taking as long as I need, and learning everything I need, so I'm fine with reading some online tutorials of your recommendation. Thanks for the help, every one.

My bet is on the PSU heading south ;-(

What's something I could do to try and check that? If it is the issue, I'm willing to try and change it myself, but would you guys recommend that for someone who doesn't do this stuff all the time? I know a fair amount, and have dug in many a computer's internals, but I know the PSU can be a bit dangerous if not handled right.