Troubleshooting power-related problems can sometimes be a nightmare. That’s because the symptoms of power problems can stretch from simply not turning on at all, to seemingly random shut-downs in the middle of doing something.
The best place to start, is to first unplug any extra devices like USB printers, external drives, or even internal components like CD drives or extra hard-drives. The important thing during the process is that after removing each variable from the equation, you must test to see if the problem still remains. That way, you’ll know that this most recently removed device is the culprit.
Let’s say you’ve removed all the devices you can, and the computer still won’t turn on. At this point, your best bet is to replace the power supply with a known good one. The power supply is the box that you plug the actual power-cord into, and once you open up your desktop tower, you’ll see that that it doesn’t seem as such a daunting task to replace after all. Just remember where each of the cables are plugged into, maybe even take a picture before you unplug everything.
When you pick out a power supply to test with, make sure that it has plenty of power to supply your whole system. You really can’t have TOO much power, as even today’s 1000watt beasts are able to operate efficiently enough to save on your energy-bill. Only when the computer is working hard, will it draw more power. That’s why sometimes power-related problems (perhaps on a cheap power supply with inadequate wattage specs) only show themselves when you’re playing a game, or watching a video, or performing a virus-scan, or any other processor-intensive activity.