Desktop PCs obtain their power from a fixed power supply. When you see power cord at back of PC; this connects straight into power supply which is placed in PC case. Power supplies can fail because of many problems. Few can be solved others; will need changing power supply. Power supplies are not costly and quite simple to change.

Checking Power

1. General problem with power supplies is no power. Check outlet and ensure it is ready. Take out any power strip or UPS and connect PC straight into a good outlet. Also ensure power cord going to PC is good and that it is totally connected into power supply.

Power Supply Switches

2. A little slider switch is on power supply. This switch is generally red and is marked 115V or 230V. This is voltage setting for region of world you live in. Ensure that switch is set in agreement with local voltage. Also, there is generally a rocker switch marked with a circle and a straight line; this rocker switch must be set with line side pressed down and circle up. The line shows power supply is on.

Overheating Power Supply

3. Other problem is overheating. If PC turns off after some minutes or hours, this is problem. PC power supplies have a ventilation fan and vents that should be cleaned occasionally. If PC is in warranty, call seller; if not clean the cooling vents. Detach power cord; take out cover and vacuum the vent on power supply. Then vacuum the vent slots on power supply. Also clean other vent holes in PC.

Overloading

4. Power supplies are rated to hold only so much existing. Each device connected into PC draws power from power supply; occasionally these devices can fail and draw too much power. Detach each exterior device except keyboard, mouse and monitor. Apply power to PC. Then check every device individually to see if that device is causing power supply to shut down. Also, if you have many devices connected into PC, you may overload power supply.

Replacing Your Power Supply

5. If above steps do not repair problem it is quite simple to change power supply. Search if you have an AT or ATX power supply and what size power supply you want. You can order a standard power supply On-line for less than $50. When changing power supply, check where cables are connected, take out old power supply, install new one and connect cables.