How to tell if your power supply is failing

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When a computer starts acting strangely—it shuts down on its own, won't start, or smells burnt—we almost always look at the graphics card, RAM, or processor, but we rarely think about the power supply as the source of the problemHowever, it is the component through which all the energy of the equipment passes, and if it fails, it can take the rest of the parts with it.

Before panicking, it's helpful to understand how a PSU (Power Supply Unit) behaves when something is wrong, what symptoms to watch for, and How to safely check if the power supply is failingIn addition, we'll see why they break down, how to extend their lifespan, and in what cases it's best to leave the equipment turned off and call a technician.

Why a power supply might fail

A power supply doesn't last forever, no matter how good the brand is or how many years of warranty it offers; over time, wear and tear, voltage spikes, or temperature problems can occur that can cause the power supply starts to behave erratically or simply stop working.

One of the most important factors is the age of the source and internal wear of its componentsCapacitors, MOSFETs, and other electronic components lose capacity over time, especially if the power supply has operated for many hours near its power limit or in a very hot environment.

They also have a significant impact electrical interference and the quality of the installation in your home or officeUnstable electrical networks, large motors connected to the same circuit, or old installations can generate electrical noise that forces the PSU to activate its protection systems and, in the long run, damage its internal components.

The dreaded Voltage spikes and overvoltages are probably the most common cause of failureAlthough modern power supplies include protection against overvoltage, short circuits, and other hazards, they are not infallible, especially when the voltage surge is very strong or the electrical installation is faulty. In these situations, part of the internal circuitry can be damaged.

El Heat is another silent enemyIf the tower has poor ventilation, is placed against the wall, the dust filter is completely clogged, or the power supply fan fails, the internal temperature of the PSU will skyrocket. Operating it like this for many months drastically reduces its lifespan and increases the risk of sudden failures.

Finally, there is one cause that is often overlooked: using a power supply with insufficient power for the installed hardwareIf you install a demanding graphics card or upgrade your processor without checking the power supply unit (PSU), you may be forcing it to run at full capacity. This not only generates more heat but also subjects the internal components to constant stress, accelerating their degradation.

Clear symptoms that the power supply is failing

Detecting a faulty power supply isn't always as obvious as the PC not turning on; often it manifests as intermittent failures that seem to originate from other components. Therefore, it's helpful to know the most common symptoms. to relate certain strange behaviors to a possible problem in the PSU.

The PC does not turn on or does absolutely nothing.

One of the most direct symptoms is that, when you press the power button, the computer It shows no sign of life: no lights, no fans, no soundsBefore blaming the source, a couple of basic checks should be done.

The first thing is to verify that The power cable is properly connected and the plug worksIt seems obvious, but a faulty power strip or a switched-off power strip can confuse anyone. Try the cable in another device or a different outlet to rule out an external problem.

If that's okay, check the rear power supply switch and power button on the caseIn some towers, the front panel power button may break or become disconnected from the motherboard. If you have some technical knowledge, you can briefly short the power pins on the motherboard (where the button is connected) to check if the problem is with the button or if the power supply is actually not responding at all.

When the PC remains dead even with the jumper on the motherboard and the power supply switch activated, everything points to the fact that The PSU has stopped working completelyIn that scenario, the realistic solution is usually to replace it, since repair is not usually worthwhile for a home user.

The computer shuts down or restarts for no apparent reason

One of the most frequent symptoms of an unstable power supply is that the equipment Shuts down suddenly or restarts randomlySometimes it happens right after starting a game or performing a demanding task, other times even on the desktop without doing anything special.

This behavior may be due to the fact that The power supply is not capable of delivering sufficient continuous power When the system demands it, especially when the graphics card and processor are both using a lot of power simultaneously. It's also possible that the PSU's protection circuit has been damaged by a power surge and starts cutting off the power in response to any anomaly.

However, it's important not to forget that the Sudden shutdowns can also be caused by excessive processor temperaturesIf the CPU overheats because the thermal paste is dry If the heatsink is clogged with dust, the system itself will shut down to prevent further damage. That's why it's important to check temperatures with monitoring software before assuming the power supply is the problem.

If the processor cooling is in good condition, the thermal paste is relatively new, and the system fans are clean, the focus shifts back to the PSU. In this scenario, an old, low-quality, or undersized power supply is a very strong candidate for causing random restarts and shutdowns.

Blue screens of death (BSOD) and graphics-related crashes

The infamous Windows Blue Screens of Death (BSOD) are usually associated with driver or RAM failures, but they can also be a sign that The source is delivering dirty or unstable power.This is especially suspicious when the errors appear when starting a game or a graphically intensive application.

At those times, the graphics card needs more voltage and amperage on the +12V lines, and if the power supply cannot provide that power stably, The GPU or the motherboard itself can generate fatal errors which end in a BSOD. The error message sometimes refers to the video driver or the graphics card itself.

If, after formatting the system, updating drivers, and checking the RAM, the blue screens continue to appear just when the graphics card is under the most stress, there are two clear suspects: the GPU itself or the power supplyA useful test is to install the graphics card in another PC with a known quality power supply; if it works without errors there, then the original PSU is likely the problem. If you don't know which GPU you have, consult [website/resource/etc.]. How to find out what graphics card you have.

Unexpected game and large application crashes

Another less dramatic, but very typical, symptom is that Demanding games or programs close on their own without displaying clear messagesYou're playing a game peacefully and suddenly, your desktop crashes. Or you're working with editing software and, without warning, it closes.

When the power supply does not filter the current properly or It cannot maintain a stable supply under high loadsEven small spikes or drops in power can cause erratic behavior in the graphics card or processor. Instead of shutting down the entire system, the failure may result in partial crashes, brief black screens, or application closures.

If your PSU has plenty of power on paper, but you're experiencing frequent game crashes during peak load times, it's possible that The problem isn't total wattage, but internal quality and electrical stability.This is a very typical case in cheap or OEM power supplies that promise many watts but lack good components.

Strange noises from the power supply fan

When the power supply fan starts making metallic noises, squeaks or knocks as if something were rubbing against the bladesThis is a sign that the bearings are nearing the end of their life or that there is an excessive buildup of dirt.

These noises may not mean that the power supply's electrical circuit is damaged yet, but they do indicate that The cooling system is not working as it should.If the fan fails completely, the PSU will overheat and eventually die prematurely, often with some scares in the form of power outages or even a burning smell.

Sometimes it's enough to perform one thorough cleaning, removing lint and coarse dust so the fan runs smoothly and quietly again. But if the noise is clearly coming from the bearings and doesn't go away, it's advisable to replace the fan or even the power supply if you're inexperienced or the warranty is still valid.

Smell of burning, sparks or smoke: fountain on the verge of collapse

The clearest and most dangerous symptom of all is noticing smell of burning coming from the tower, hear a small clicking sound, or even see smokeAt this point there is no doubt: something serious has gone wrong inside, usually a blown capacitor or a serious problem in the surge protection system.

If, while using your PC, you hear a "pop", the computer suddenly shuts down, and you immediately detect a burning electrical smell, the wisest course of action is immediately disconnect the computer from the power supply.Do not attempt to continue turning it on or disassemble the power supply if you are not entirely sure what you are doing, as some components may retain an electrical charge.

Often, when opening the PSU (something not recommended if you're not a technician), you'll see Swollen capacitors, with rust or traces of dried liquidThis confirms that the power supply has reached the end of its lifespan and must be replaced urgently, because using it in this state could damage other components or pose a fire risk.

Another worrying indicator is the appearance of very irregular coil whine-like noisesThe system is characterized by beeps that rise and fall in intensity every few seconds, accompanied by system instability. Along with bulging capacitors, these sounds are indicative of advanced internal degradation.

The PC starts up, but shuts down after a few seconds

There are cases where, upon pressing the button, the computer It turns on fans and lights for a few seconds and then turns itself offSometimes it gets stuck in a boot loop without ever loading the operating system.

This behavior may be due to either a unstable power supply such as faulty connectionsTherefore, before blaming the PSU entirely, it's worth checking that the 24-pin ATX connector, the CPU EPS cable, and the graphics card's PCIe connectors are firmly attached to the motherboard and components. If you're unsure how to identify them, consult [reference to a specific tool/resource]. How to view my PC components.

If everything is properly connected and the problem persists, the power supply may be faulty. detecting any type of internal fault or overload and cutting off the power supply for protectionMany modern motherboards have diagnostic LEDs that can indicate CPU, RAM, or GPU errors; if these light up just before the system shuts down, it's worth ruling out those components. But if there are no clear warnings, the power supply is again the prime suspect.

How to check if your power supply is failing: the paperclip method and safety

In addition to looking at the symptoms, it's possible to do a basic test to check if the source, at least, It is capable of starting and powering its own linesThe most popular method is the famous "clip-on jumper" in ATX power supplies, which should be done carefully.

The first is Turn off the power supply's rear switch or unplug the power cordFor safety, never work on the power supply unit (PSU) while it's plugged in and you're handling the main power connector. If you want to be extra thorough, you can also discharge any residual power by pressing the PC's power button for a few seconds with the power cord unplugged.

Next, it is recommended Disconnect all cables from the power supply that go to the motherboard, graphics card, and the rest of the componentsIf you don't know how to identify them, ask. It's not mandatory, but it helps prevent any part from receiving unstable stress during the test and allows you to concentrate on the PSU's performance on your own.

With the power supply now off the load, locate the 20/24 pin ATX connectorIn that wiring harness, there will be a single green wire (PS_ON) and several black wires (COM or ground). The clip method consists of bridging the pin of the green wire with any of the adjacent black pins.

To do this, use a A well-insulated metal clip or a piece of rigid wirePlace the ends on the corresponding pins, making sure they don't touch any other contacts. Once the jumper is in place, connect the power cable and turn on the power supply's rear switch.

If everything is done correctly, The PSU fan should start spinningIn some semi-passive power supplies, the fan only activates above a certain load, so the blades might not move even though the power supply is on; in these models, you can usually hear a slight buzzing sound or check with a multimeter if there is voltage at the Molex or SATA connectors.

When, after correct bridging, the power supply shows no signal (no fan, no noise, no voltage at the outputs), it is normal to assume that The PSU is broken and needs to be replaced.However, this test only confirms whether the power supply "starts" or not; a power supply can turn on but remain unstable under load and cause the problems described above.

If you're not comfortable handling connectors or aren't sure you're doing it right, the wisest thing to do is go to a specialized technical serviceThey will be able to measure the voltages with appropriate tools, test the PSU under different load levels, and accurately confirm whether the power supply is the culprit.

How to prevent your power supply from breaking down prematurely

There's no magic recipe to make a fountain last forever, but there are good practices that help a lot. prolong its life and reduce the chances of failureUltimately, we're talking about a critical component that deserves more care than others.

Choosing the right power (and not always going for the bare minimum)

When buying a PSU, it is vital that Calculate the total power consumption of your equipment and leave a reasonable safety margin.If your setup is around 450W at maximum load, there's no point in installing a 500W power supply, because you'll have it working near its limit almost all the time.

Ideally, you should choose a source of a little more power than recommended by the CPU and GPUespecially if you plan future expansions. Working in a moderate load zone improves efficiency, reduces internal temperature, and significantly extends the lifespan of components.

Avoid OEM sources and opt for reliable brands

The cheap OEM power supplies that often come with many pre-built PCs may seem like a bargain, but They tend to use low-quality components and very basic protections.This translates into more electrical noise, less stability, and a higher probability of premature failure.

Although they cost a little more, it's much better to opt for well-known brands with good technical reviews And, if possible, with a multi-year warranty (some manufacturers offer up to 10 years). Keep in mind that efficiency certifications (80 Plus, Bronze, Gold, etc.) are a good indicator, but they don't guarantee quality on their own; it's advisable to look at in-depth analyses.

Protect the power source from power surges and outages

If your area experiences frequent power outages, thunderstorms, or voltage fluctuations, it is highly recommended to use some additional protection system for the power supply and the rest of the equipmentTwo very common options are UPS and surge protection power strips.

Un UPS (Uninterruptible Power Supply) It not only gives you a few extra minutes of power in case of an outage, but it also filters voltage spikes and drops, delivering a much more stable current to your PC. An in-line or mid-to-high-end UPS is ideal, although the price increases with the power you need.

If your budget is tight, you should at least have a surge protectorThese power strips incorporate an internal mechanism that cuts off the power when they detect a dangerous spike, preventing it from reaching the power supply and other computer components.

Keep the source clean and well refrigerated

Dust is the number one enemy of any PC, and the power supply is no exception. To extend its lifespan, it's important to... Perform regular cleanings to prevent dust from accumulating on the fan or ventilation grillesWith a soft brush and an air blower or compressor, you can remove the most obvious dirt without needing to open the PSU.

Unless you have electronics knowledge and the warranty has already expired, it's best to Do not open the power supply casingIn addition to voiding any remaining warranty, you could damage sensitive internal components or expose yourself to residual electrical charge.

It is also essential to take care of the general ventilation of the tower and the physical location of the sourceDo not place it against a wall that obstructs the air outlet, use dust filters in the area where it draws in fresh air, and ensure there is reasonable airflow through the chassis.

A source of healthy, high-quality food is foundation of any stable PCUnderstanding its symptoms, knowing how to check it, and giving it a minimum of care with good ventilation, cleaning, and electrical protection can save you a lot of scares, data loss, and even having to replace expensive components prematurely.