How To Replace Your PCs Power Supply Unit (PSU)

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The Power Supply Unit or “PSU” is one of the most important components inside of your computer, after all, it’s the component that provides power to all your other components. 

Choosing the right power supply unit to meet your requirements doesn’t have to be a hassle. If you’re in the market for a new PSU, there are two rules I live by when shopping for one:

  1. Always go bigger – As an IT professional, I like to be prepared and to future proof things. When I look at PSU’s, I always think to myself – Will I be upgrading something in a few years time? If your answer is yes, I would definitely go bigger.
  2. Don’t go cheap – There are many bargains out there for PSU’s I recently bought a Cooler Master PSU for ÂŁ25 on sale! It was more than enough for that particular build. With this statement, I am referring to budget power supply units that haven’t been tested or rated. The PSU can potentially destroy other components! It’s important to know that even decent PSU’s have the potential of going bang. This actually happened to me a few years ago. It was a relatively new PSU from a decent brand and it wasn’t operating under heavy load but trust me, I heard it and it killed my motherboard! 


Why Would I Replace My PSU? Some of the reasons include:

There may be a number of reasons you are looking to replace your PSU. What ever your reason may be, it’s important to do some research before making a purchase!

  • Your computer doesn’t power on – I would be extremely careful with this one as just because your PC isn’t powering on doesn’t mean your PSU had died, it could be another component. That’s why it’s important to troubleshoot by taking every single component out of your PC, one by one and attempting to power it on every time you remove a component. If in doubt, take your PC to a local repair shop.
  • You are upgrading a component e.g. Graphics Card – If you are planning to do some upgrades on your rig, it’s important to know how much power you need. A Power Supply Calculator such as this one will be able to help.
  • You’re building a new rig – You don’t have to be replacing your PSU, you may be building your own computer!

How To Replace Your PSU

In this section, I will show you how to replace the PSU inside of your computer.


I am not responsible for any damage or injuries caused by following this guide. This guide is a reference only. If you are not comfortable replacing hardware, please take your PC to a local repair shop.

Some Useful Tools:

Below are some tools I recommend checking out:

  • PSU CalculatorAvailable here – Good for determining your PSU 
  • PC Part PickerAvailable here – Good if you are building a PC or if you want to determine compatibility

To make things easier for you, I actually made a video on my new sub channel on YouTube; PC Tips With Dom. It’s a channel dedicated to computers and tutorials. So if you haven’t already, subscribe now!

I decided to make this guide after finding myself in the market for a new PSU. I was looking to turn some old PC parts I had lying around into an ESXI Server, but I soon found that my spare PSU unit which I used for testing was dead. So after doing some research and comparing some prices I found a decent Cooler Master PSU on Scan.

Video Guide:

Hopefully the video guide made sense! 

If you are interested, in my PSU selection, I made a first impressions video on my main channel Tech With Dom and you can check that out below:

Are you in the market for a new PSU or do you have any questions? Let us know in the comments!