I have a situation. One of the computers I work with (desktop, early 2000's gateway) doesn't turn on anymore. The last time it was working was 3 hours prior to when I began working with it. The power button was flashing, showing hibernation. The screen was off. I moved the mouse and nothing happened, so I pressed the power button once. The hard drive started spinning as expected but then the computer strangely shut itself off instead of turning back on. Afterwards, I pressed the power button a few times but it just doesn't turn on. I looked at the back of the computer at its ethernet input/output. It is still flashing. What could be the source of the problem?