How to Install a Power Supply for Your Home Computer

psu_install_need_more_powerSo, I turned on the computer the other day and a few seconds later the screen goes blank followed shortly by a very loud BOOM! After building computers for years I knew right away that the power supply blew a Capacitor. Don’t panic though if this happens!  I’ll show you how to replace probably the easiest component in your computer – the Power Supply.

So What Happened?

The sad part is that I knew it was going to happen and waited for it to die before I replaced it. The Old Power Supply was starting to give some weird power spikes indicating that it was about to die. Finally one day I turned it on and I get a very loud BOOM! From years of working on computers I knew instantly (OK a little praying too) that a Capacitor in the Power Supply blew up.

The old PSU was a no-name 1000 watt Power Supply that was the workhorse for the past 3 years when I originally built the computer. (Don’t build your own? This article still applies for your Computer!)

Old Power Supply

One Dead Power Supply

What caused it to finally die? Dust. Yup, dust is probably the #2 killer of Computers out there. What is #1 killer for Computer Hardware? Heat. And since Dust is a great conductor of heat… they go side-by-side in killing your computer right now.  If you don’t already own some canned air and blow out your Computer? It is just a matter of time you will be replacing parts or the entire Computer!

Old Power Supply - Dust

Dust Killing My CPUS

What’d You Get To Replace It With?

So off to NewEgg I go! I purchased a Corsair 650w replacement Power Supply. I bought it for a steal for around 80 bucks. I went with a cheaper smaller model, as this computer is now relegated as my Home Theater PC. I only turn it on to play some music or watch some Netflix through my TV.


Corsair Replacement PSU


How Do You Swap Them Out?

NOTE: Few things to remember here. First and most important. The Power Supply is no joke. DO NOT remove the cover from the Power Supply as the parts inside could still hold residual electricity which could severely INJURE OR KILL YOU.  Second – You should make sure you are wearing an Anti-Static strap and even be so paranoid as to use an Anti-Static Mat as well.

Failure to follow these practices? I am in no way whatsoever liable or responsible for any damage incurred by you.

With that being said? Um.. sure I use an anti static mat/wrist strap….

If the warning above freaks you out? Just CALM DOWN and take a deep breathe. As long as you unplug your Computer from the wall, keyboard, mouse etc… and hold down the Power button for a few seconds? It should discharge any residual electricity in your computer. I have personally worked on thousands of PC’s in my career and I’ve never been zapped.

Quick Checklist and Time

It is a simple process like I said before.

  • Get a Philips Head Screwdriver
  • Unplug your Computer from the Wall, Keyboard, Mouse, Video, USB etc..
  • Open Side Panel from Computer Case
  • Unplug Power Supply from Components and Motherboard
  • Unscrew from back of Computer Case
  • Pull the Old Power Supply from the Case
  • Install the New Power Supply
  • Screw it in to the Back of the Case
  • Plug in Power Cables to Components and Motherboard.
  • Replace Side Panel to Computer Case
  • Plug Computer In and Test

Total Time: About 20-30 minutes.

Tools Needed

A Screwdriver. More specifically a Philips Head that is preferably non-magnetic. Magnets and Computers = Bad. This one happens to be a $0.99 purchase from Ace Hardware.

CPU Install Tool

A Screw Driver

Unplug Your Computer

Yup, the first step is to unplug your computer. Unplug it from the Wall, Disconnect anything you have connected to it so it is just the bare computer case. Make a note of how everything plugs back in by the way and if needed take pictures so you don’t get lost underneath your desk going “OK, where does this plug into?”.

This is also a good time to take some Canned Air to blow all the dust out from your computer! But… I would suggest doing this inside your garage, or at least on your back porch.

Open Computer Case

Computer Case Open

Unplug Your Components and Motherboard

It’s a fairly simple process to unplug the devices. Most of the power cables pull off the components with a gentle tug. While a few of the cables might have a “clip” to make sure it stays securely in place. These (like your motherboard and video card) might take a bit of force. You DO NOT need to use a tool to pop them loose. Just gently tug from the base of the cable taking note of how they are clipped on.

If you need a tool to pull them off? You’re doing it wrong!


Everything Unplugged!

You’ll notice what a tangled snare of cables I had with my old Power Supply. It was a pain to work on and the cables prevented proper airflow for the components in the system. Now days you can purchase a Modular Power Supply – which allows you to use only the cables you need vs. all the extra cables you have to find a way to stuff somewhere inside your case.

Pull Out the Old Power Supply

It’s usually just 4 Screws at the back of the computer case. Mine happens to be at the bottom – but they are typically located at the top. I would suggest laying it on it’s side (open end up!) that way when you unscrew the old one it won’t go crashing down onto all of your internals possibly damaging them.

Install the New Power Supply

Now that the old one is out. It’s time to install the replacement one.

Place the replacement Power Supply into the Computer Case and line up the holes. Go ahead and screw it in using either the screws from the old Power Supply – or you can use the nifty new ones that some manufacturers provide.

CPU Power Supply Install

Line Up the Holes

And speaking of placement. Make sure the internal fan of the new Power Supply is facing Down (for standard Computer Cases) or Up (for those that allow you to mount it on the bottom of your case).

Power Supply Fan

Fan Side Down!

Now just plug the power cables back in. I try and keep things neat. (Lost some pictures apparently – whee)


Plug In CD Roms

Its pretty simple to plug in the cables. Just match up the plugs and apply gentle pressure to seat them in.






Plug in to Power Supply

This is why I like a Modular design versus a standard Power Supply. It makes life so much easier installing and routing it to make it look cleaner.





Had to Remove the Heatsink

The only bad part for me during the install was I had to remove the Zalman CPU Cooler for the Processor to plugin the necessary 8-pin power to the motherboard. Oh well I was able to get a fresh coat of thermal grease on the CPU and re-install it. (Not to mention I apparently installed it backwards?!?! – Even the experienced guy makes mistakes.)




Before and After

I’m going to show you the before an after shots to see how much of a difference using a Modular design vs. Standard Power supplies look after they are installed. To me it looks much cleaner and the airflow has improved dramatically!


So we are looking at the mess before I replaced the Power Supply. It was a tangled mess of cables and was just plain scary to look at!

Before - OLD PSU

Before – OLD PSU


Now here is the After shot. I did my best to try to keep things neat and clean. I also found a bunch of dust bunnies hiding in spots I didn’t think to check the last time I cleaned it out. (yuck) It looks a little cleaner – but the airflow is much better!  Although you can’t really notice it from the shot ( stupid new camera) it actually has a ton more breathing room in the case allowing better airflow.




So Did It Boot? (Troubleshooting)

As you can see – it isn’t all that difficult to replace your Power Supply yourself. Just takes a screwdriver, a bit of  time to figure out how to install the cables, and your done!

Oh.. and did it boot? Yes, of course it did! If it didn’t though?

  • I would have to re-check all the connections, make sure everything has been seated correctly.
  • Make sure I had the back Power switch turned to the “On” position.
  • Clear out the CMOS battery – and a few other things before I gave up and returned the Power Supply as a possible faulty unit.

Hope you all enjoyed the article. Leave a comment below if you have any questions!

PC Parts Blowout! DIY deals at eye-popping prices only at

About Jason Mathes

Geek, Gamer, Blogger. I share my passion for gaming, technology, and WordPress. You will find reviews, tutorials, and more inside!If you have any questions or want to discuss the article? Find me on one of the Social Media buttons below. Or use the Contact Page up top!


  1. Craig says

    Nice to see a post with some effort put into it with images and useful information rather than just a bunch of text that makes no sense.

    Kepp up the good work

    • says

      Thanks – unfortunately I had a new camera to work with and about half of the pictures ended up getting cut out. (And no way did I want to tear it apart again lol).

  2. Dave says

    I came to have a look at your install a computer power supply post (which actually confirmed how I was going to do it) and ended up scrolling through the site and spending more than hour doing so. Great site, some interesting posts and links. I really enjoyed it – it would be easy to become addicted but other things call :).

    Thanks for the time and effort you’ve put into this site.


  3. James says

    Thanks for all the useful tips! I for one makes sure that I am able to clean my computer of dust at least once a month. If I don’t what I experience is that my computer just shuts down by itself but after cleaning it, it’s okay again.

    • says

      Thanks for dropping by. Glad you enjoyed the article! Dust is a definitely a killer for computers. It creates a thermal layer which causes heat issues. So make sure to break out the canned air and “dust” the internals of your computer at least annually.

  4. Brain says

    hehehe… Definitely you have to do a so much hard work for creating this post. You nicely explained all the things from starting to end for installing SMPS also with snapshots. Teachers will also not train us like you. Lol…. :)