Diagnosing a High-Pitched Noise Coming from Your Power Supply Unit (PSU)

Diagnosing a High-Pitched Noise Coming from Your Power Supply Unit (PSU)
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Your computer’s Power Supply Unit (PSU) is a strange and often frustrating component in any system. Some last for a few years and some last for a few months. One thing, however, is certain. Other than not working, the most annoying aspect to a PSU is when it starts making a high-pitched or funny sound.

Whether the sound is consistent or intermittent, loud or soft, or high- or low-pitched, the sound is likely caused by two possibilities. Read on to learn how to isolate and diagnose a funny, high-pitched sound coming from your computer’s power supply.

Verifying the Source of the Noise

Although a funny, high-pitched sound may appear to be coming from your power supply, it may actually be coming from another component inside of your computer. Remember that the power supply is usually located at the top and back of a computer case. Many sounds can appear to come from the back of a computer because it is the most open part of the case.

Open up one of the side panels on your computer and turn the computer on. With the side open, you should be able to tell whether it is the power supply making the funny or high-pitched sound. After you verify that it is the PSU making the noise, you can diagnose the problem and decide what to do.

Why PSUs Make Funny, High-Pitched Sounds

There are two main causes of PSU making strange noises. Other than the fan, there are typically no moving parts inside of a power supply unit. Since the fan or fans is/are the only moving parts, they are often the culprits behind funny noises.

Unfortunately, few power supplies give you the option to replace the fans and under no circumstances should you open up the power supply to get at any part inside. PSUs contain capacitors that can hold powerful electrical charges even when powered off. If one of your PSU fans is making a high-pitched noise, then bring it to a qualified electrician to replace the fan or lubricate its bearings or sleeves.

The second cause of high-pitched noises is the several copper coils within the PSU. Over time, these coils are heated and cooled as the PSU is switched on and off. After a while, the copper metal can become brittle and create squeezing to screeching noises as they heat up and then cool.

Copper Coils Inside of a PSU

Again, there is really no way to fix this problem. It is too dangerous for an amateur to open the PSU and fix it and the cost of fixing the power supply isn’t worth it in comparison to buying a new one.


The top two main causes of high-pitched noises coming from a power supply are the fan or fans and brittle copper coils. Unfortunately, there is little computer owners can do to fix this annoyance. Your best bet would be to replace the power supply.

Before you do, make sure the PSU is to blame. Remember that your computer contains several moving parts including case fans, video card fans, and hard drives. Since the backs of computer cases are most open, many computers owners assume that the funny noise is coming from the PSU. Check it out before you spend any money.