How To Check Power Supply On PC Windows 10: A Step-by-Step Guide

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Edgar Nicov

How-To

6 min. read

Published on October 31, 2025

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A computer’s power supply unit (PSU) is a critical component, responsible for delivering the necessary electricity to all other parts. Problems with the power supply can lead to system instability, crashes, or even complete failure. Knowing how to check the power supply on your Windows 10 PC is a valuable troubleshooting skill that can save you time and money.

This guide will provide you with a step-by-step approach to diagnosing potential power supply issues. We’ll cover both software-based checks and physical inspections, enabling you to determine if your power supply is functioning correctly or needs replacement.

How Do I Check My PC’s Power Supply on Windows 10?

Checking Power Supply Using Software

While software can’t directly read the power supply’s output, it can monitor voltages and temperatures that indicate potential problems.

Download and Install Monitoring Software:

Download a reputable hardware monitoring tool like HWMonitor or CPUID HWMonitor.
Install the software following the on-screen instructions.

Run the Monitoring Software:

Launch the installed monitoring software.

Monitor Voltage Readings:

Look for voltage readings under the motherboard or PSU section.
Pay close attention to the +3.3V, +5V, and +12V rails.

Compare Readings to Expected Values:

Compare the voltage readings to the expected values.
Acceptable ranges are typically within +/- 5% of the specified voltage (e.g., 11.4V to 12.6V for the +12V rail).

Check for Fluctuations:

Observe the readings over time, especially while the computer is under load (e.g., gaming or running demanding applications).
Significant fluctuations or readings outside the acceptable range can indicate a failing power supply.

Visually Inspecting the Power Supply

A visual inspection can reveal physical signs of damage or failure.

Power Down and Unplug the Computer:

Completely shut down your computer.
Unplug the power cord from the back of the computer case.

Open the Computer Case:

Open the computer case by removing the side panel(s). Refer to your case manual for instructions.

Locate the Power Supply:

The power supply is typically a metal box located at the top or bottom of the case, usually near the back.

Check for Physical Damage:

Look for any signs of physical damage, such as bulging capacitors, burnt components, or loose wires.

Smell for Burnt Odors:

Sniff around the power supply for any burnt or unusual odors. A burnt smell is a strong indication of a failing component.

Inspect the Fan:

Ensure the power supply fan is clean and spins freely.
A malfunctioning fan can cause the power supply to overheat and fail.

Testing the Power Supply with a Multimeter (Advanced)

This method requires some technical knowledge and caution. If you’re not comfortable working with electronics, seek professional help.

Gather Your Tools:

Obtain a multimeter, a paperclip, and the ATX power supply testing guide (available online).

Disconnect Components:

Disconnect all components from the power supply (motherboard, drives, etc.).

Perform the Paperclip Test:

Bend a paperclip into a U-shape.
Insert one end of the paperclip into the green wire slot and the other end into any black wire slot on the 24-pin ATX connector. This will simulate the power-on signal.

Plug in the Power Supply:

Plug the power cord back into the power supply. The fan should start spinning.

Test Voltage Rails with Multimeter:

Set the multimeter to DC voltage mode.
Place the black probe on a black wire (ground) and the red probe on the wire you want to test (+3.3V, +5V, +12V).
Compare the multimeter readings to the expected values.
If the voltages are significantly out of range, the power supply is likely faulty.

Identifying Common Power Supply Issues

System Instability: Frequent crashes, blue screens, or random restarts.
Difficulty Starting Up: The computer may fail to power on, or it may power on intermittently.
Overheating: The power supply may become excessively hot to the touch.
Loud Fan Noise: The power supply fan may be excessively loud or make unusual noises.
Burning Smell: A distinct burning odor emanating from the power supply.

Tips for Maintaining Power Supply Health

Ensure Adequate Ventilation: Make sure the power supply has sufficient airflow to prevent overheating.
Use a Surge Protector: Protect the power supply from voltage spikes and surges.
Clean Regularly: Dust can accumulate inside the power supply, causing it to overheat. Clean it periodically with compressed air (after unplugging it, of course).
Upgrade When Necessary: If you upgrade other components that require more power, ensure your power supply can handle the increased load.

Power Supply Diagnostics

Regularly checking your PC’s power supply is essential for maintaining system stability and preventing hardware failures. By following the steps outlined above, you can identify potential problems early and take corrective action.

FAQ

How long should a PC power supply last? A good quality power supply should last between 5 to 10 years, depending on usage and environmental factors.

Can a bad power supply damage other components? Yes, a failing power supply can deliver incorrect voltages, which can damage the motherboard, CPU, GPU, and other components.

What are the signs of a failing power supply? Signs include system instability, random crashes, difficulty starting up, loud fan noise, and burning smells.

Is it safe to open a power supply for inspection? It’s generally not recommended to open a power supply unless you have experience working with electronics. Power supplies contain capacitors that can store high voltages even after being unplugged.

How often should I check my power supply? It’s a good practice to visually inspect your power supply every 6 months and perform software checks periodically.

Power Supply Comparison

Feature	High-End PSU	Budget PSU
Efficiency	80+ Gold/Platinum/Titanium certified	80+ Bronze certified
Lifespan	7-10 years	3-5 years
Protection	Over-voltage, over-current, short-circuit	Basic over-voltage protection
Components	High-quality capacitors and components	Standard capacitors and components
Price	Higher	Lower
Recommendation	For high-performance gaming or workstation PCs	For basic home or office PCs

Keeping Your PC Powered On

Regular maintenance and diagnostics are key to ensuring your PC’s power supply is functioning correctly. By taking proactive steps, you can extend the lifespan of your power supply and prevent costly hardware failures.