How to Install a Power Supply Unit in Your PC: Step-by-Step Guide

The process to integrate the PSU into your build is quite simple and straightforward. Having said that, you can not still overlook the possible hazards because of an improper installation. For instance, damage to the PC components or even short circuits.

So, it is vital, you understand the process of installing a power supply unit whether you’re building a PC or replacing the old PSU with a new one.

In this article, I’ll be explaining the step-by-step procedure to install a new PSU into your PC.

How to Install a Power Supply Unit in Your PC

Getting Things Ready

Here’re a list of few things you need to have before starting up:

  • right size screwdriver, Phillips head preferred.
  • tray for holding screws, preferably a magnetic one.
  • Anti-static wrist wrap to ground yourself. If you don’t have one, proceed with installation in an anti-static area. You can frequently touch a metal object (unpainted one) during the installation process to drain the static charge.
  • Cable ties or Velcros.

Now that you have gathered the necessary tools, it’s time to get into the actual process. Let’s Start!

Attach Power Supply Cables to the PSU

You may skip this step if you have a non-modular PSU (PSUs with all cables pre-attached to them.)

Otherwise, you need to connect the cables to the PSU manually. You will generally find five kinds of cables with your modular PSU, like the ones that came with my fully modular Corsair RM 850x.

Grab the required cables for your setup and connect them to the power supply unit. Make sure the connection is secure and tight.

Remove the Side Panel

The next step involves removing the side panel. If you are in-between the PC building process, you probably already have the side panel off. If not, read on.

Each PC case has its unique way of removing the side panel. It normally depends upon the manufacturer.

In most cases, you can either do it by removing the thumb screws on the edges of the panel or unfastening the tiny screws on the edges of the back panel.

You may require removing only the left side panel or both sides depending upon whether your PC case has a shroud or not.

For instance, the NZXT H700 PUBG case that I bought for my high-end gaming rig requires removing both side panels before I can install the PSU.

Mount the PSU

Now that you have removed the side panel, you will get access to the PSU compartment, often located at the bottom of the PC case.

In the case of my NZXT H700,

Grab the PSU and align it properly into its bay such that the air-intake-fan faces downwards and the AC cord inlet side faces backward.

If there is no sufficient ventilation at the bottom, you can also face the fan upwards. However, your PSU must have compatible mounting holes to support the orientation.

Tighten up the screws to attach the PSU to the chassis.

The steps should be similar in case of other PC cases too.

Note: Only mount the fan upside if your PC has a proper cooling system. Otherwise, the hot air within the PC case can overheat the PSU, ultimately causing thermal throttling in the long run.

Route the Cables

The next thing you should focus on is the proper routing of the power cables. PC cases these days have a dedicated cable routing path with ample space behind the motherboard tray, as you can see in my mid-tower NZXT H700.

You can direct the power cables through these paths, then guide them through the cable management holes in your PC case. You may use zip ties or Velcro to organize them.

I recommend you guide these cables through the holes/slots closest to the connectors on the motherboard/devices, so that the connection becomes easier later.

Connect PSU to the PC components

Once you are done with cable routing, it’s now time to connect them to the motherboard and other components.

Simply connect the 24-pin ATX motherboard connector to the ATX header, like I have done on my GIGABYTE TRX40 AORUS MASTER.

Similarly, plug the 12V CPU power connector to the 8-pin ATX_12V CPU header.

Likewise, connect the PCIe, SATA and Molex connectors depending upon your requirements.

If you are having difficulties figuring out the cables and where they go, we have an in-depth article on power supply connectors.

Finalizing Installation

Now you’re only one step away from giving life to your machine. But wait, don’t reattach the side panel or power on your PC yet. Instead, double-check everything first.

Make sure if the power cables are securely attached on both sides. Check if the PSU is properly mounted, and verify the cable routing too. Once everything is set,

Turn off the power switch on your PSU (press the 0 side.)

Attach the AC power cord to the unit and turn on the power supply from the wall outlet.

Switch on the PSU (press the 1 side.)

Turn on your computer. If the computer boots up successfully, shut down your computer and reattach the side panels to your PC case.

Your PC should turn on as expected. However, sometimes due to other causes the PSU may not turn on. In such cases, you need to troubleshoot the power supply.

Moving forward, if anything does not seem to work, you might have to replace your PSU. Although replacing the power supply unit is as easy as installing the new one, make sure you find the right product.

I suggest getting a high efficiency power supply unit that has an 80 PLUS Gold or Platinum rating. This way, it doesn’t waste a lot of energy as heat and can even save you money on your electricity bill over time.


Mohamed SAKHRI
Mohamed SAKHRI

My name is Mohamed, and I'm the creator and editor-in-chief of Tech To Geek. Through this little blog, I share with you my passion for technology. I specialize in various operating systems such as Windows, Linux, macOS, and Android, focusing on providing practical and valuable guides.

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