Compaq intel pentium 42.8ghz512mb
How old is your computer? Did you recently have a power outage or anything? Most the time if a computer won't turn on, something in it went bad OR an outlet is bad. Try this:
1. Make sure that the power switch is on, the switch in the back (on the power supply itself) is turned on, and everything along those lines is functioning.
2. If that doesn't work, and it will not power on AT ALL, make sure the cords are plugged firmly in place, including the surge protector and/or the power cord itself.
3. Try resetting the surge suppressor and/or plug the computer into a
different outlet in the surge suppressor. Try other items in that surge suppressor (or even in the wall outlet, if that's what you're plugged
into) to make sure that the outlet itself is working.
4. If your computer is plugged directly into a working wall or surge suppressor outlet, try a different power cord.
5. If your surge suppressor works, your wall outlet has power to it, and you are using a known-good power cord in the computer, you will have to go into more in-depth investigation as something inside the computer likely went bad. It could be the video card, motherboard, CPU fan, power button, or the power supply itself. Start by testing the video card and the power supply by (one at a time) swapping out a known-good component for the one you suspect may be bad. If it won't turn on after that, try swapping out the next and try it again. If it still will not work, it could be something more serious such as the motherboard or power button.
it could be a bad power supply or a bad motherboard. Other problems might cause issues, such as a bad video card.