How to check if PSU is causing your PC won’t turn on issue

If you are reading this post, you must be thinking that your computer’s Power Supply Unit (PSU) is either dead or malfunctioning. A PSU that’s not working properly often results to any of the  boot-related issues we cover in this previous post. Well, worry no more as you’re definitely in the right site to start troubleshooting your PC’s power supply unit.

Although older computers ran a higher risk of encountering a PSU failure, having a new computer does not necessarily mean your PSU is fine, especially if you’re having trouble booting the phone up. Before we tell you how to fix a power supply issue or how to know if it’s the one causing your PC not to turn on, let us give you a brief description of what it is.

Before we proceed, we want you to know that we are now accepting questions about Windows computers in general as well as requests for assistance regarding a Windows problem. Windows problems can sometimes be difficult to diagnose so kindly make sure that you give us very detailed description of the problem. You also want to mention relevant history that may have led to the issue. The more information that you can provide, the higher the chance of us diagnosing the issue more efficiently. We also expect that you mention whatever troubleshooting step/s that you may have done before contacting us in order to prevent repeating them in our article. Again, more details you can give us, the faster it is for us to pinpoint the cause and its corresponding solution.

What is a power supply unit?

Every computer needs power to run a complex set of components in the motherboard as well as some peripherals like the ubiquitous mouse and keyboard pair. This power requirement is handled by one device called the power supply unit or PSU. Technically, the main function of the PSU is to convert AC (alternating current) voltage coming from the mains into DC or direct current or continuous voltage. PC components can’t run on pure AC so the raw power from your wall outlet needs to be converted into DC first in order to be useful for your computer.

If you haven’t heard of the power supply unit or seen one ever, that’s normal for many average PC users. Even PC gaming enthusiasts who are supposed to be well-versed with all things PC don’t pay much attention to this component. It’s in fact the most neglected part when buying computer or computer parts. The usual stuff that many computer buyers consider includes the processor, motherboard, video card, hard drive type and capacity and memory. Sometimes, it’s even forgotten! It’s ridiculous but it’s true. Having a good power supply in their computer is usually the last thing many users have in mind when getting a computer. That’s unfortunate since having a high quality power can significantly increase durability of other components.

A PSU is usually indicated by a three-prong outlet usually at the back of the case, while in laptops and tables, the PSU is usually part of the power cord that connects to the wall outlet. PSUs are rated by their corresponding wattage. Some may be rated at 65 watts while others over a thousand or more. Another difference within PSUs are their amps rating. Some may have 10 amps while others can carry up to 65 amps.

So how do you know that your computer’s power supply unit no longer works?

In most cases, bad power supply unit manifests itself in random shutdowns, sudden blue screed of death problem, or some erratic behavior of a PC during use. Learning the signs of a malfunctioning PSU is therefore important in fixing whatever issue it has resulted to, but also in the prevention of damaging other components. Below are some of the common symptoms of a failing PSU that users must be aware of.

Computer randomly shuts down without apparent reason

If you notice that your PC has started crashing on its own or has become unstable, one of the first things that you should check is the power supply unit. Although instability can also be caused by other issues, including software ones, there’s no reason to skip checking the power supply unit. If you can narrow down the possible causes by excluding software causes first, the next best thing to check then is the power supply unit. Diagnosing the true cause of frequent crashes can be tricky but we recommend that you start with checking for possible software issue first. If you notice that the crashes seem to appear only when your PC is under load, that is when your computer tries to do CPU-intensive tasks or when gaming, the power problem may be traced to the PSU. If you installed a powerful video card in the system and the computer appears to crash or power off only when starting graphics-intensive task like 3D modeling, you should consider a bad PSU as the culprit. Graphics cards can draw huge power from the PSU and if the latter is not equipped to handle it, a shut down may result.

There’s unusual noise and odor coming from the case

A PSU has its own dedicated fan to keep itself cool during operation. If you notice an unnatural noise coming from the PSU area, it may be the fan going out. You should immediately turn the computer off to avoid overheating the PSU, which may result to major failure of other components as well. If the PSU has already overheated, it may also produce bad odor from burnt plastic or connectors. Make sure that you turn the machine off right away to avoid starting an electrical fire. Although rare, there had been instances wherein a damaged PSU has resulted to a fire.

Computer turns on, then turns back off immediately

Like all other cases of unexplained crashing issues, sudden shut down following a boot up may be caused by other factors. But again, you don’t want to skip checking the PSU.

Computer boots up but then proceeds to Blue Screen of Death (BSOD)

Blue screen of death issue can have a lot of possible causes but if it occurs right after booting up, chance are the PSU may be involved. Make sure to troubleshoot the BSOD issue based on the STOP error that comes with it. If you can’t take note of the STOP error or code because the PC restarted right away, do some basic software troubleshooting first. If software troubleshooting won’t yield a software cause, the most likely reason for your problem may be a bad PSU.

Computer is totally unresponsive and won’t turn on

If pressing the power button won’t turn the phone at all, you must have a classic example of PSU failure. If your power supply unit has an on and off switch, make sure that it’s set to On position. If that won’t chance anything, be prepared to test your PSU.

Factors that can cause the PSU to fail

In many cases, there’s often no warning a user will get if a PSU fails. Sometimes, outside factors can cause a PSU to stop working or to behave erratically. Below are some of the possible reasons why a PSU stops working:

  • Blockage of vents and/or overheating
  • Unstable voltage. Fluctuations in voltage coming from the main line outside your phone can cause a PSU to fail. Sometimes, energy companies may intentionally lower the voltage in some areas to address some emergencies in other areas.
  • Sudden voltage spike. Like in reduction of voltage, sudden rise in voltage can break a PSU. Lightning strikes on a main line may all of a sudden provide unnecessary voltage so make sure to turn your computer off if you’re in an area with frequent lightning storms.
  • Dirty or dusty environment. Dirt and dust can often attack the fan and the inside components of PSU. If your computer is located in a dust-exposed area, you can expect that that your PSU will not last long.
  • Aging. Like in almost all electronic devices, the process of growing old can affect the PSU as well. We’ve known of some high quality PSUs lasting over 10 years but many fail after over 4 years. If you are using an older computer, consider replacing the PSU to maintain quality power source for the entire system.

How to take care of your PSU

PSUs can die anytime, especially if it’s been running for several years already. You can, however, prolong your PSU by doing simple maintenance and care. Below are some of the things that you can do to extend the life of your computer’s PSU.

Minimize dirt and dust. Dust is often one of the top killers of PSUs so avoid positioning your computer in a dusty place. Keep your computer in an air-conditioned room or at least, inside a room that’s not too exposed from dust. If you have the time, consider removing the PSU from the computer and cleaning it at least once every few months to prevent dust from clinging in the fans and in other places.

Avoid overheating. Aside from cleaning and keeping dust away, you also want to make sure that your computer and PSU are not exposed to a heat source. To avoid overheating, make sure to let the system rest for a couple of hours after a long stretch of usage.

Buy a high quality PSU. Good PSUs may cost a little bit more but they usually last longer compared to low quality ones.

Avoid overloading. The general rule in good PSU management is to ensure that your computer’s system requirements is only about 80% of your PSU’s capacity. This means that you should always consider not to max out the maximum wattage of your PSU when adding expansions or video cards. Be sure to consult your friendly technician if you can’t get an estimate of your PC’s power consumption.

Important note when working around PSUs

We know that we suggest opening up your computer and cleaning the PSU from time to time but we also want to make it clear that the PSU can seriously hurt you if you’re not careful. That said, we want to emphasize some important points that you should keep in mind when dealing with a PSU.

Even when unplugged, PSUs can be dangerous. Sometimes, inexperience can kill, literally. The same is true when fixing anything electronic or electrical. The PSU can store enough electricity, even when unplugged, to maim you. The capacitors inside can keep voltage charge for some time after unplugging the PSU so if you accidentally short one by mistake, you may be electrocuted.

Familiarize yourself on how to avoid killing your computer with static electricity. Removing the PSU involves dismantling some components from the motherboard and if you’re not careful in grounding yourself before touching the motherboard, you can effectively brick your system or some components. Static electricity is the reason when you sometimes get a shock when touching a doorknob or an object. Use Google on how to effectively avoid ESD or electrostatic discharge, also known as static electricity when opening your computer case.

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If you are having a problem with your Windows computer, don’t hesitate to let us know about it. We understand how frustrating computer problems can be so, more so if you can’t find the right solutions at all. Our blog exists to help PC users and Windows community deal with their problems effectively. To engage with us, just fill out the questionnaire in this link and wait for our articles to be published. In order to help as many people as possible, we only provide our solutions via posts so please don’t expect that we will respond to your emails or private messages. By making all posts public, we can share our solutions to other users in a more efficient manner. We cannot guarantee a quick response so if your issue is time sensitive, please find another way to resolve your problem.

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