Is My Computer's Power Supply Unit Failing? Signs to Watch For

The Power Supply Unit (PSU) is the unsung hero of your computer. It’s responsible for converting the AC power from your wall outlet into the low-voltage DC power that all your computer’s components need to function. When the PSU starts to fail, it can cause a wide range of bizarre and frustrating symptoms that often get mistaken for other issues. A failing PSU can be a serious problem, potentially damaging other components like your motherboard or hard drive if it fails completely.

At AS Computer Solutions here in Onoway, we often diagnose power-related issues that trace back to a failing PSU. Knowing the warning signs can save you a lot of trouble and potential data loss. Before you start buying new RAM or a graphics card, consider if your PSU might be the true culprit.

Here are the key signs to watch for that indicate your computer’s power supply unit might be on its last legs.

✅ 1. Unpredictable Shutdowns or Restarts

This is the most common and alarming sign of a failing PSU. The computer might shut down randomly while you’re working, or it might reboot itself without warning.

Why it happens: The PSU can no longer deliver a stable or sufficient amount of power, especially under load (e.g., while gaming or rendering video). When a component demands more power than the PSU can provide, the system instantly shuts down to protect itself.
Try this: Pay attention to when the shutdowns happen. If they consistently occur during graphically intensive tasks, a failing PSU is a very likely cause. Also, check your computer’s Event Viewer (search for “Event Viewer” in Windows) for critical errors related to unexpected shutdowns.

🛠️ 2. The Smell of Burnt Plastic or Electrical Components

This is a red-alert sign. If you smell anything acrid or like burning plastic coming from your computer, power it down immediately and unplug it from the wall.

Why it happens: This smell indicates that an electrical component inside the PSU is overheating and burning out.
Try this: Do not try to turn the computer back on. Leave it unplugged and bring it to a professional. Continuing to use a PSU that smells like it’s burning is extremely dangerous and could lead to a catastrophic failure that fries your other components.

✅ 3. Computer Fails to Start or Stays Off

If you press the power button and nothing happens—no fans, no lights, no sound—the PSU is often the culprit.

Why it happens: A completely dead PSU can’t deliver any power to the motherboard or other components, preventing the computer from even attempting to boot.
Try this:
- Check the basics: Ensure the power cable is securely plugged into both the wall and the back of the computer. Try a different outlet and a different power cable.
- Check the PSU switch: Many PSUs have a physical on/off switch on the back. Make sure it’s in the “On” position.

🛠️ 4. Loud or Excessive Fan Noise

The PSU has its own fan to keep it cool. If this fan is constantly running at high speed and making a lot of noise, it could be a sign of trouble.

Why it happens: If the PSU is struggling to deliver power, it will generate more heat. The fan spins faster to compensate, leading to a loud, constant whirring noise. A failing fan bearing can also cause a grinding or whining sound.
Try this: Listen closely to the fan noises. If the PSU fan is particularly loud, or if the sound is grinding or rattling, the PSU may be failing.

✅ 5. The “Blue Screen of Death” (BSOD) or Other Random Errors

A failing PSU can cause corrupted data or voltage irregularities, which can trigger a Blue Screen of Death (BSOD) or other strange errors.

Why it happens: The PSU might be delivering inconsistent voltage to your components, leading to data corruption as it’s being written to your hard drive or processed by your RAM.
Try this: While a BSOD can be caused by many things, if it’s accompanied by other signs on this list, a failing PSU is a strong possibility. Use a tool like BlueScreenView to analyze the BSOD error codes; if they are vague or different each time, it may point to a hardware issue like a failing PSU.

🧰 Still Unsure? Bring It to the Pros

Diagnosing a failing PSU can be tricky and even dangerous if you don’t know what you’re doing. It involves working with high voltage components. If you’re experiencing any of these symptoms, the safest course of action is to have a professional take a look.

At AS Computer Solutions, we can:

Use specialized tools to test your PSU’s voltage output and performance under load.
Accurately diagnose if the PSU is the root cause of your problems.
Safely replace the PSU with a new, reliable unit.
Check for any collateral damage caused by the failing PSU to other components.

🏡 Local. Reliable. Ready to Help.

The PSU is a critical component that should not be overlooked. Don’t wait for a complete failure to address the problem. If you’re seeing any of these warning signs, give us a shout. We’ll get to the bottom of your computer’s power issues and get your system running reliably again.

Call or visit us today: 📞 (780) 967 0215 🌐 wwwsite.ascsonoway.com 📍 Onoway, Alberta 📧 [email protected]

Is My Computer’s Power Supply Unit Failing? Signs to Watch For