Why does my monitor make a buzzing or humming noise?

The most common cause is coil whine — a high-frequency buzz from an inductor or capacitor inside the monitor's power supply vibrating as current passes through it. The second most common cause is dirty or unstable power reaching the monitor from the wall outlet, a power strip, or a shared circuit, which makes internal components vibrate audibly. On USB-C portable monitors specifically, the buzz is often tied to power delivery load — high brightness plus active speakers plus simultaneous laptop charging over one cable pushes more current than the connection handles cleanly.

Is monitor buzzing dangerous or a sign it's failing?

Usually not. A faint hum, especially one that only appears at high brightness or under heavy load, is normal coil whine that doesn't affect the monitor's lifespan or performance. It becomes a real concern only if the buzzing is accompanied by heat, a burning smell, flickering, or visual instability — those combined symptoms point to an actual hardware fault and warrant unplugging the monitor and having it checked.

Is coil whine covered under warranty?

Usually not. Most monitor manufacturers treat coil whine as a cosmetic, non-defect noise rather than a hardware failure, since it doesn't affect display performance — so a support ticket is more likely to get troubleshooting tips than a replacement. Checking your specific manufacturer's policy before assuming coverage is worthwhile, but budgeting for a self-fix (different outlet, different cable, or a lower refresh rate) is the more realistic plan.

Can a bad cable or power strip cause a monitor to buzz?

Yes. A low-quality power strip or a shared, dirty circuit can introduce electrical noise into the power reaching the monitor, which makes internal components vibrate at an audible frequency. Plugging the monitor directly into a wall outlet — ideally on a different circuit than a computer, refrigerator, or other high-draw appliance — clears this cause in under a minute and costs nothing.

Why does my portable USB-C monitor buzz more than my desktop monitor?

Portable monitors pull both video and power over a single USB-C cable, and the laptop and monitor negotiate how much current moves across that one connection. Running the monitor at high brightness, with its built-in speakers active, while the same cable is also charging the laptop, pushes the power delivery link harder than a desktop monitor's dedicated power brick ever has to work, which is why coil whine shows up more often on portable displays under those exact conditions.

Will lowering the refresh rate stop monitor buzzing?

Often, yes, for coil-whine specifically. Dropping from a high refresh rate like 144Hz to 120Hz reduces the load swings the power supply has to respond to, which can quiet or eliminate an audible whine tied to fast, repeated current changes. It's a workaround rather than a fix, but it's free and reversible, making it worth trying before assuming a cable or hardware fault.

Monitor Buzzing or Humming? Causes and Fixes (2026)

Quick Answer: A buzzing or humming monitor is almost always coil whine — a high-frequency noise from an inductor or capacitor in the power supply vibrating as current passes through it, most noticeable at high brightness or heavy load. Dirty power from a shared outlet or cheap power strip is the second most common cause, and on USB-C portable monitors specifically, high brightness plus active speakers plus simultaneous laptop charging over one cable is a frequent trigger. Plugging directly into a wall outlet, capping refresh rate, and swapping cables clear the cause in nearly every case without a repair or replacement, since most manufacturers treat coil whine as a cosmetic non-defect rather than a warranty issue.

A monitor is silent by design, so any buzz or hum stands out immediately — but the underlying cause is rarely the panel itself. It’s almost always the electronics feeding it power: an inductor or capacitor vibrating at a frequency inside the 20 Hz–20,000 Hz range of human hearing, triggered by current fluctuations that are completely normal for the component but happen to land where you can hear them.

Buzzing causes and fixes, ranked by likelihood

Cause	How to tell	Fix
Coil whine	High-pitched buzz that gets louder at high brightness or under heavy GPU load	Lower brightness slightly, cap refresh rate or frame rate, or enable V-Sync/G-Sync
Dirty power / shared circuit	Buzz is present regardless of brightness or content, worse when other appliances are running	Plug directly into the wall, ideally a different circuit; skip cheap power strips
USB-C power delivery load (portable monitors)	Buzz appears at high brightness with speakers on while the laptop is also charging	Power the monitor separately, or use a full-featured USB-C cable rated for video + data + power
Loose power connection	Buzz changes or cuts out when the cable is nudged or repositioned	Reseat the power cable firmly at both the monitor and the outlet
Built-in speaker interference	Buzz only comes through the speakers, not from the chassis itself	Move speaker cables away from power cables, or use headphones/external speakers to isolate

Why it happens: coil whine and power delivery load

Coil whine comes from a basic property of inductors and capacitors: when current passes through a coil, it vibrates, and if that vibration happens to fall inside the 20 Hz–20,000 Hz range of human hearing, you hear it as a buzz or whine. The frequency of that current varies with the load on the system, which is why the noise so often tracks directly with brightness or GPU activity rather than staying constant. On USB-C portable monitors, the same effect gets an extra trigger: the laptop and monitor negotiate how much power moves across a single cable, and running high brightness with active speakers while the same connection is also charging the laptop pushes more current through that link than a desktop monitor’s dedicated power brick ever has to handle.

APC 11-Outlet Surge Protector with USB — Best Fix If It's Dirty Power

Best for shared/noisy circuits · 11 outlets + 2 USB ports · 3020 joule rating · about $30

Gives the monitor a dedicated, filtered outlet instead of sharing a noisy circuit with a computer, refrigerator, or other high-draw appliance — the single most common non-coil-whine cause of a persistent hum.
Far more effective than a bare power strip, which can itself introduce electrical noise on cheaper models rather than filtering it out.
A one-time, inexpensive fix worth trying before assuming the monitor itself is at fault.

If it’s not dirty power

Lower brightness slightly and listen. Coil whine that tracks with brightness confirms the cause immediately and costs nothing to test.
Cap your refresh rate or frame rate. Dropping from a high refresh rate like 144Hz to 120Hz, or enabling V-Sync/G-Sync, reduces the rapid load swings that drive audible coil whine.
Plug straight into the wall. Bypass any power strip and use a different circuit than your PC or other high-draw appliances if the buzz doesn’t change with brightness.
On a portable monitor, separate power from video. Use a dedicated USB-C power adapter for the monitor while keeping a plain video connection, or switch to HDMI plus separate USB power entirely.
Swap the USB-C cable. A cable that isn’t rated for full video, data, and power together can pass enough current to light the panel while still behaving unstably under load.
Isolate the speakers. If the buzz only comes through the monitor’s built-in speakers, route speaker and power cables apart, or test with headphones to confirm the noise isn’t audio-specific interference.

Buzzing by the numbers

20 Hz–20,000 Hz. The range of human hearing that coil whine has to fall inside to be audible at all — most inductors and capacitors vibrate outside this range under normal conditions, which is why coil whine shows up on some units and not identical-model units sitting next to them.
144Hz to 120Hz. A commonly cited refresh-rate step-down that reduces the load swings driving coil whine enough to quiet or eliminate it on an affected gaming monitor, without any cable or hardware change.

The bottom line

Start by listening for whether the buzz tracks with brightness or GPU load — if it does, it’s coil whine, and capping your refresh rate or frame rate is the fastest free fix. If the buzz is constant regardless of content, move to the power side: plug directly into the wall, skip cheap power strips, and give the monitor its own outlet with a filtered surge protector like the one above. Portable monitor owners should separate power from video first, since USB-C power delivery load under brightness and charging combined is the single most common trigger on that category. Most manufacturers treat coil whine as a cosmetic non-defect rather than a warranty claim, so working through these checks yourself will resolve it faster than a support ticket in nearly every case. Chasing a different display symptom instead? Our monitor green tint guide covers a color-cast issue rather than a noise one, our monitor flickering guide covers strobing and brightness instability, our monitor won’t wake from sleep guide covers a power issue that shows up as a black screen instead of a sound, and our monitor black screen guide covers the menu-button and flashlight tests for a black screen that isn’t tied to standby at all.