Power Supply Failure, Noises, Computer not Turning On Power supplies like hard drives will fail eventually. Power supplies however almost never give any warnings that they are about to give up other than the computer just not turning on. Power supply failure early symptoms: There are strange noises coming from the back side of the computer where the power cord plugs into the power supply. Nothing happens when the computer power button is pressed. The computer turns on for a few seconds and then turns off.  (Sometimes this is unfortunately associated with motherboard failures.) Computer turns on for a while, but when games or other applications are using the computer steadily, it will turn off or I get a blue screen. Some of the most common issues with power supplies is bad leaking capacitors.  This same issue can happen on a motherboard as well.  Capacitors can blow, bulge or leak caused by many things such as:  power spikes, power outages, and age to name a few.  Below are a couple of pictures of bulging and leaking capacitors.  I cut away the wires inside the power supply to make things a bit easier to see.  Never take a power supply apart, it is dangerous and you risk electrocution, even if the power supply is unplugged.  Capacitors are made to hold high amounts of electrical charges.  The human body only needs 1/8 of an amp to stop your heart.  Power supplies on average produce 10 - 30 amps.     As you can see the capacitors are leaking brown goo from the center of the plus sign above.  The other ones are bulging. From this angle you can see the capacitors bulging and leaking clearly. The power supply above caused the computer it was in to immediately turn off when the user inserted a CD into a CD/ROM drive.  It was not able to supply adequate power to all the components in the computer so it browned out, or as the user would say, just rebooted without warning.  Power supplies are common to fail, if you are comfortable in opening your computer and replacing your power supply, we recommend "Ultra" brand power supplies, which you can find over at Tiger Direct.com.   The power supply testers above can be purchased at Tiger Direct, all are very easy to use, simple.  Always, exercise caution when working with electric parts or open computers. If you have any of these symptoms, it would be a good idea to have the system checked out. Frequent power supply failures will ultimately lead to further system damage and/or data corruption, which will cost you more hard earned dollars in the long run.