Power supply is found on every personal computer. It is device where power is received from the alternating current and converted to direct current that is useable by the computer. It is located inside the CPU distinguished by cooling fan and the power-cord receptacle.

Since the power supply receives the first surge of alternating current, it heats fast when used and cools down when the computer is shut down. The heat produced by electric surge can cause the components to overheat more frequently than other parts of the CPU. As the consequence, the power supply is the particular part that is most prone to failure.

One most common symptoms of power supply failure is the inability of power to come on. Several reasons might cause this to happen. The first thing you should do is to check whether the socket has power. To do this, all you have to do is to unplug your computer and try other plug. It can be a radio or a lamp. If the radio or the lamp work, then you have to check whether your computer plug is already busted. This might be a rare circumstance but it is probable to happen.

Another thing worth checking is the voltage setting. At the back of the CPU where the power supply is visible, you can surely locate the voltage selector. Check if it is on the right setting, which is 220v. On a 110v country, set the power supply to 110V.

If in case the power comes on but there is no live screen, you may try shutting down the computer again. Booting for at least two times would make the power supply to stabilize. Usually, this happens when the motherboard demands more timing from the current power supply.

But if you have done this for several times and there is no sign of live screen, it is more likely that the motherboard protects itself. Dont react violently if this happens; just buy a new power supply that the motherboard suggests. It is cheaper to buy power supply than to replace the motherboard so you should be thankful your motherboard does not accept the power supply.

Another common cause of power supply failure is the fan defect. If the power supply is working properly, you should not hear any cranking sound. You must also feel a breeze from the power supply. If you hear a cranking sound, there is no need to panic. Make sure that the sound is not caused by any solid object interfering with the blades of the fan. If you notice that the power supply fan creates noisy whistle-like sound, the cause could be the capacitor.

Power supply fan can be replaced. But make sure that it is removed by technicians because if you remove it improperly, you might get electrocuted even if the power has already been removed.

In the case of PC shutting down randomly by itself, make sure that the power supply maintains its right temperature. Also check if the fan is working properly. It could also be the cause of unstable power supply. If this happens, it is advisable to replace your power supply.

These are some but most common power supply problem. If one of these happens, it is always wise to check everything first before buying a new power supply.