Why my Acer Aspire One 725-0478 won't stay on?

I just had a similiar issue. It could be anything. It could be a failing motherboard, failing power supply, bad ram, anything really.

A good place to start is to remove the side case of the computer and then remove and reseat the ram. Do this one at a time. Take both ram out try to boot, put one in, try to boot, put the other one in by itself, try to boot.

If you don't get it going, unplug your video card if you have one that isn't built in. Try to boot.

If that doesn't work, unplug everything and try to boot. When I say everything I mean the graphics card, hard drives, everything. You should at least get a failure message if it wants to boot.

If that doesn't work. Unplug and replug in every cable on the motherboard, making sure that you blow out any dust with air duster or a hand air pump or something like that.

If that doesn't work, you can disconnect the power supply and test the voltages using a multimeter. There are tons of guides online how to do it.

If that doesn't work, you probably have an issue with your motherboard.

Does it show anything on the screen when it boots or does it just flash on and off with no message?