This wikiHow teaches you how to install a power supply for a Windows desktop computer. The power supply is what facilitates the flow of energy from an electrical source to the other components of the computer. Keep in mind that if your computer came pre-assembled, you don't need to install the power supply, although you may need to replace it at some point.
Step 1. Find a power source for your computer
The power supply you buy depends on your motherboard and the size of your computer's case, which means you'll need to research your motherboard model to see which power supplies will fit. You can usually find power supplies in stores or tech departments, as well as online stores like Amazon and eBay.
Make sure you buy a power supply that is optimized for your region. Power supplies for European markets use a different voltage setting than those used in North American markets
Step 2. Gather your tools
You will need at least one screwdriver (usually a star screwdriver) to open the CPU case, which is usually the right side of the CPU case when looking at the back of the case. You may also need a different screwdriver for the power supply. Look at the screws that came with the power supply to determine whether or not this is the case.
Step 3. Ground yourself
This will help prevent you from inadvertently damaging your computer's internal components with static electricity.
You can buy an antistatic strap to help you stay grounded while you work
Step 4. Open the computer case
At this point you should be looking at the internals of the computer.
Step 5. Lay the computer case on its side, with the exposed side facing up
Step 6. Adjust the voltage switch on the power supply
If there is a voltage switch on the power supply, change it to 110 V or 115V. This will ensure that the power supply provides plenty of power without damaging the components to which it is connected.
Not all power supplies have voltage switches, and those that normally do have the switch set to the standard of the region for which it was purchased
Step 7. Find the intended location for the power supply
Power supply units (PSUs) are typically located at the top of the cabinet, this is the reason why the power cord is usually plugged into the rear top section of the cabinet.
- Check your computer's instruction manual for the proper location of the power supply unit, or look for a rectangular cutout on the back of the cabinet.
- If you are taking out an old power supply, look for a socket on the back of the cabinet to find the power supply.
Step 8. Insert the power supply
The power supply should have a distinctive "top" with plugs and a fan, as well as a "bottom" with a fan. The "back" should face the back of the cabinet, while the "bottom" should face the inside of the cabinet.
If you have an old power supply in your computer, remove it first
Step 9. Screw the power supply into place
With the "back" of the power supply unit pressed against the back of the cabinet, insert the included screws to secure the power supply in place.
Many CPU cases have shelves that the power supply will stand on
Step 10. Connect the power supply to the motherboard
Find the main power cable from the power supply (usually the one with the largest connector) and connect it to the long, rectangular port on the motherboard, then connect the secondary power cable to the motherboard.
- Depending on your power supply and motherboard, you may not have a secondary power cord.
- The connector used to connect the power supply to the motherboard is generally a 20 or 24 pin connector.
Step 11. Connect the power supply to the other components of the computer
Using the smaller cables, connect the power supply to the computer's hard drive, CD drive, and graphics card. If you have other components in your cabinet (for example, a lighting system), you may need to connect them as well.
Step 12. Shut down and plug your PC back in
Put the cover back on the PC and then stop it and plug it back into the wall and your monitor.
Step 13. Turn on your computer
If everything is connected and plugged in properly, the power supply fan should turn on and the computer will boot as usual. If you hear a beep and nothing happens, then something is not connected properly inside, or the power supply is not providing enough power to the components.
- ALWAYS use the new cables that came with the new PSU. NEVER try to reuse old cables from the old PSU, as this can burn out the motherboard.
- Connections from the power supply to internal components should be tight, but not forced.
- You will likely have extra cables after you've finished connecting the power supply to the computer components.
- Remember that all power supplies contain multiple capacitors inside that retain power even after being turned off. Never open or insert a metal object into the fans, as you may risk an electric shock.
- When removing the screws from the power supply, hold on to the power supply. The torque produced when removing one screw can affect the removal of the others.