Every operation the PC performs is based on the presence or absence of electronic signals. When you plug your PC’s power into your 120-volt AC (alternating current) wall socket, you actually plugging in the PC’s power supply. The power supply, in turn, transforms the voltage into the 5-volt DC (direct current) that the computer can use. Within your PC’s system unit, in turn, other devices, such as the mother board and disk drives, plug into the power supply. Occasionally, a power supply will fail, and you must replace it.
Recognizing A Failed Power Supply
When your PC’s power supply does not work, your PC will not start. In addition, when the power supply fails, you will not hear the PC’s fan whir. The PC’s fan in contained within the power supply.
Do not jump to the assumption that your power supply is bad just because your system does not start and you cannot hear the fan whir. Instead, first double-check the PC’s power plugs to ensure that they are plugged in correctly. Next, verify that the wall outlet into which the PC is plugged is working (you may have to plug a different device, such as a lamp into the outlet to verify the outlet is working).
If you are using a surge suppresser, remove the suppresser and plug your PC directly into a working wall outlet. When a surge suppresser captures an electrical spike, it will normally trip an internal breaker. Most surge suppresser have reset button you can press to restore the suppressor’s normal operation.
Replacing Your PC’s Power Supply
- To replace your PC’s power supply, first power off and unplug the PC system unit. Next remove the system unit cover. Place the screws your remove in a safe location.
- Within your system unit, locate the small power supply cables and their plugs.
- To remove the plugs, you might need to rock the plugs, you might need to rock the plugs gently from right to left. Be careful to grasp the plugs, not the wires attached to the plugs, or you might damage the power-supply cables.
- There are normally several screws that hold the power supply to the back of the system unit. Remove these screws and place them in a safe location.
- The power supply should not lift out from your system unit easily. Be careful as you lift the power supply from the system unit. The power supply is heavier than it looks.
- Make sure you do not set the power supply (or let it fall, in the case of a tower configuration) on top of any fragile components.
- Place your new power supply into the system unit and replace the screws that attach the power supply to the system unit.
- Next, plug in your motherboard, disk drives, and other devices you may have unplugged from the power supply.
Note: The power supply plugs are shaped so that can be plugged in only one way.