The power supply seems like an easy install, but get ready for spaghetti. Now that you have your drive data cables connected, your fans connected, and your case wires connected to your motherboard, your computer inside may seem like a jumble of wires, but you haven't seen anything yet. We've saved the power supply until the end because the amount of cabling is about to double.
When you consider that each DVD drive, your hard drive, maybe your graphics card, and the motherboard requires power and that power has to arrive at the device needing power via a power cable, then all of a sudden you've got twice as many cables running all over the inside of the case. But there is a method to the madness, so let's get started.
Unwrap your power supply from its packaging, and take it out of the wrapping material. If you didn't get a modular power supply you'll see a bunch of cables coming out the back of the power supply.
If you got a modular power supply, you won't see as many cables coming out the back, but you'll still see some. You'll also see ports on the back for the modular power cables. I like modular power supplies because it reduces the number of non-useful cables in your computer. You only use the cables you need. If you have a modular power supply, make sure the extra cables snap into the power supply ports with a click so it won't come out inadvertently later when using the computer.
Let's install the power supply in the case. The power supply fits into its own notch in the case. Fit the power supply into the case so the on-off switch comes out the back of the case, and the power supply fan is pointed toward the open air on the inside of the case. Do not block the fan by having the fan pointed at the case side. Also make sure none of your previouse wires are trapped by the power supply.
The power supply is held to the case with four Phillips screws attached from outside the case. Make the screws tight, but not super tight. The cables should come out the back of the power supply inside the case.
There should be at least three cables coming out the back. One is a big wide 24-pin ATX connector that is the main power to your motherboard. You should easily find where that goes on the motherboard. It has a latch on the side that matches with a hook on the plug so you put the plug in the correct direction.
There should be at least one 8-pin ATX 12v and one 6-pin PCI express coming out the back of the power supply. One of these will go into the second power connector on your motherboard. This may be a 8, 6, or 4-pin socket, and usually the 8-pin power plug can be broken in half to make two fours. Check your motherboard, or your motherboard diagram to find this connector.
Your graphics card may take a 6-pin power cable. Some graphics need additional power and some don't. Look for a power connector plug on the graphics card, if you don't see one, the motherboard will power the card.
Each drive needs power. The IDE drives use a 4-pin Molex connector. The Molex connector is rounded on two edges to match the connector which is also rounded on two corners, so you can't put it in the wrong direction.
The last power connectors you will need is the SATA power connector. This is a 15-pin slim connector with an L-shaped appendage on the end, like the data cable had, so you can't hook it up the wrong way. Make sure they're pushed in tight to the disk drive. You'll need one power connector per drive, one power cable usually has two connectors.
Congratulations! You've installed all your hardware inside your case. Before we put the covers on the case we'll will want to test things out, which we'll write about next.