How to Know If Your Computer Power Supply (PSU) is Failing
Power Supplies Fail Sooner or Later
Much like hard drives in computers, all power supply units (or PSUs for short) eventually fail. Also like hard drives, it isn't a matter of if, it is a matter of when and why. In this article, you will learn how they fail, what some of the common symptoms are, and how to diagnose the problem.
So, What is a Power Supply Unit, Anyway?
Inside a computer, a PSU is the device that converts alternate electricity (the electricity from your outlet, normally 110V) to direct current to the components inside the case. Looking from the outside, it's the three-prong plug that plugs into your socket. Laptops' are much the same, except they're external: A block and cord that attaches to the back and plugs into the wall.
Every power supply is different. Some (typically for laptops) may have a low output of 65 watts, while others might output 1,000 watts or more. Some may only have 10 amps, while others output 65 amps.
When the PSU is no longer delivering the power your computer needs, things start getting wonky: See below for the signs.
Symptoms of a Failing Power Supply
More often than not, you just don't get any warning that the PSU is going to quit on you. However, sometimes it may do one (or more) of the following before it kicks the bucket:
- Strange noises may emit from the back of the computer case where the cord is located.
- When the computer is turned on, nothing happens. Sometimes this may coincide with a flashing light on the front of the computer or an indicator on the back of the PSU (if equipped).
- The computer turns on for a couple of seconds and then turns right back off. While this can be a power supply issue, it may also indicate motherboard failures.
- The computer is on for a while, but maybe while you're playing a game or using another application it just randomly turns off without warning. It might also display a blue screen of death.
When gaming is involved, one must realize that video cards these days require a lot of power and amperes to run correctly. When purchasing a PSU, be sure you have the wattage and amps needed for the equipment inside of your computer, especially the video cards.
So, Why Do PSUs Fail?
Power supplies just fail. Failures can be instigated by something you've done but sometimes, the unit simply gives up. Below is a list of common factors that send a unit to its grave.
- Age: Most warranties last from 5-10 years, but that's no guarantee. Its life also depends on how often you use your computer.
- Electric Interference (lightning, power spikes, etc.).
- Dirt/Foreign Substance (cigarette smoke, house dust, etc.).
- Brown-Outs: Intentional or unintentional drops in voltage. These load reductions are sometimes used in emergencies, like during a heat wave when everyone is using their A/C.
- Overheating and/or Ventilation Failures.
The most common reasons are overheating and lightning. However, if you are a cigarette smoker or the computer is in a dusty environment, rest assured you will be replacing your PSU sooner rather than later.
Can Anything Be Done to Prolong the Life of a PSU?
Yes, there are a few things that will help you get the most out of a power supply. You should be able to extend its life beyond the manufacturer's warranty. Just remember that it isn't going to last forever.
- Make sure you are not maxing out the wattage with the additional equipment you install. The power supply should exceed your system's requirements by a minimum of 20%.
- Don't cheap out and purchase a junky unit. A nice one will cost a little more, but will go a long way.
- Keep it as dust-free as possible.
- Keep it, along with the rest of the computer, under 80 degrees.
Keeping the air quality clean may be difficult in some scenarios, so getting an air filter would be useful. Occasionally cleaning the system out will also prolong its life. The computer needs to breathe, or it will overheat and die.
This is the device I use to check the power supply. It's an inexpensive alternative to having a professional use the same device to check the PSU for you.
I was at a client's house to have a look at her computer. She said it wouldn't start. I had already assumed the PSU was bad, but I didn't expect to find even more when I arrived. It turned out the power supply had zapped every single component in the computer except a single DVD-ROM drive at the very top of the case. None of the components (motherboard, CPU, hard drive, etc.) had any signs of a surge such as burnt chips or even the smell of them being burnt.
In the end, the only other devices that powered up with the computer with a working PSU were the system case fans. I wasn't there when the power supply blew, but I would have to imagine that it released some sort of electromagnetic pulse through the whole system.
This was a weird case, and an educated guess as to what happened; however, there really isn't any other explanation. The hard drive wouldn't even spin. Only the devices that produce a natural electromagnetic current (fans) and the DVD drive (which was higher than the power supply) survived.
Lesson to be learned: Back up your data!
This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.
© 2009 Ryan Hutzel