If your PC is making an unusual humming or buzzing noise, there are a few potential causes to investigate. The humming or buzzing noise could be coming from the computer’s internal components like the power supply, cooling fans, or hard drive. It’s important to pinpoint the source of the noise and address any underlying issues to prevent damage or failure.
Quick Overview of Potential Causes
Here are some common reasons a computer might make humming or buzzing noises:
- Issues with the power supply – If it’s making a loud humming, it could be failing.
- Problems with cooling fans – Excessive dust buildup, bearings wearing out or fans hitting wires can cause buzzing sounds.
- Failing hard drive – A constant low hum from the hard drive may indicate it’s failing and needs to be replaced.
- Interference from peripherals – Devices like external hard drives plugged into a USB port can sometimes cause buzzing noises.
- Coil whine from components – Some components like power transistors or inductors can emit a high-pitched whining sound when in use.
- Cables touching fans – Wires from devices rubbing against cooling fans can create humming or buzzing.
How to Pinpoint the Source of the Noise
When troubleshooting buzzing or humming sounds in a computer, it helps to isolate where exactly the noise is coming from. Here are some tips to pinpoint the source:
- Turn off all peripherals and external devices first to rule them out as the cause.
- Open the case and listen closely to identify the general location of the noise.
- Stop any spinning fans briefly with your finger to see if the noise changes or stops.
- Press gently against various components and cables to isolate vibrations.
- If needed, use a paper tube or mechanics stethoscope to precisely locate the sound.
Focus your troubleshooting efforts around the internal components making noise. The most common sources are the power supply, cooling fans or hard drives. But noises can also come from smaller components like inductors when under heavy load.
Power Supply Issues Causing Humming or Buzzing
If the noisy humming or buzzing is coming from the power supply, it likely indicates a problem with the PSU. Some sounds are normal from PC power supplies, but loud or excessive humming often means the PSU is starting to fail. Here are some specific issues that can cause a loud humming power supply:
- Failing fan – The built-in cooling fan bearing wears out or fan blades become unbalanced.
- Failing transformers – Buzzing transformers or chokes can indicate impending failure.
- Faulty capacitors – Capacitors are strained beyond their specs and emit noise.
- Loose internal components – Parts come loose and vibrate against each other.
- Excessive load – The PSU is overloaded and components buzz under heavy strain.
A persistently loud humming PSU often means it’s failing and should be replaced. Using a faulty power supply can damage other components or lead to unexpected shutdowns.
Troubleshooting Noisy Power Supply Issues
- Confirm noise stops if power supply is unplugged.
- Try a different power outlet in case of line power issues.
- Check if PSU fan spins properly and is not striking wires.
- Inspect for bulging or leaking capacitors on PSU.
- Test PSU with a power supply tester if available.
- Replace PSU if humming persists and other issues are ruled out.
Cooling Fan Problems Causing Buzzing
Noisy computer fans are one of the most common causes of buzzing sounds. Issues like the fan bearing wearing out, blades becoming unbalanced or hitting wires can create buzzing. Here are some cooling fan problems that generate noise:
- Faulty bearing – Fan bearing starts to wear out causing friction and buzzing.
- Imbalanced blades – Fan blades warp or wear unevenly resulting in vibration.
- Wire obstruction – Fan blades strike or rub against loose internal wiring.
- Dust buildup – Excessive dust causes grinding and buzzing from fans.
- Fan bracket contact – Fan housing vibrates against the mounting bracket.
Buzzing fans may need to be cleaned or replaced. Leaving the problem unchecked can lead to the fan failing completely.
Troubleshooting Noisy Cooling Fan Issues
- Clean fans and heatsinks thoroughly to remove dust buildup.
- Inspect fans for any obstructions or wires touching blades.
- Feel for grinding in bearings when spinning fan.
- Replace fan if bearing seems faulty or blades are unbalanced.
- Adjust fan brackets or rubber mounts to reduce housing vibration.
- Update BIOS and chipset drivers which may reduce fan speeds.
Hard Drive Failure Humming
If your PC’s hard drive is making a persistent humming or buzzing noise, it could be an indication of impending failure. The noises arise when problems occur with the drive’s internal hardware:
- Bad spindle motor – Makes buzzing or grinding noises during disk reads/writes.
- Failed ball bearings – Cause friction and hum when platters spin.
- Heads striking platters – Can create buzzing as heads vibrate against surfaces.
- Loose internal parts – Components coming loose and rattling together.
Constant humming or buzzing from a hard drive usually means it’s failing. It’s vital to backup data and replace the drive before total failure occurs.
Troubleshooting Hard Drive Noise Issues
- Use HDD tools to check drive health for reallocated sectors or failures.
- Check if noise persists when drive is powered on outside computer.
- Try a different SATA cable and port to isolate drive issues.
- Back up data and replace the noisy hard drive immediately.
Electrical Interference Buzzing
Peripheral devices connected to the computer can also be a source of electrical interference causing buzzing sounds. External hard drives, headphones, speakers and other accessories plugged into USB ports may have inadequate shielding or filtering in their circuitry to block electrical noise leakage. The buzzing occurs because the audio outputs are picking up electromagnetic interference from the USB power lines or other components. Troubleshooting steps include:
- Unplug peripherals one at a time to isolate interference source.
- Use rear USB ports which may have better filtering than front ports.
- Plug peripherals into a USB hub with isolated power supply.
- Add ferrite chokes or noise filter beads to USB cables.
- Use optical or audio-only connections like S/PDIF instead of USB.
Coil Whine Causing High-Pitched Noise
“Coil whine” is a high-pitched electronic squealing or whining noise that comes from inductors or power regulation components when under load. It arises from vibrations in magnetic coils or ceramic capacitors:
- Inductor coil whine – Magnetic vibrations from choke coils converting power.
- Capacitor whine – High-frequency ceramic capacitors vibrating.
- Voltage regulator whine – Whining from components managing power delivery.
Coil whine usually increases with higher system loads. Troubleshooting coil whine includes:
- Identify components causing whine then replace if possible.
- Limit FPS rates in games and applications to reduce load.
- Undervolt or limit overclocking which increases coil vibration.
- Adjust power settings for energy efficiency to limit whine.
But coil whine may be unavoidable based on system configuration, and does not negatively impact performance or indicate a defect.
Cables Touching Fans
If loose internal wiring is making contact with spinning fan blades, it can cause a noticeable humming or buzzing sound. This typically occurs when cables come loose from their connectors or retaining clips. The cable then drops into the path of the fan rotation. Solutions include:
- Open case and inspect fan areas for any loose cabling.
- Ziptie or twist-tie wires to secure them away from fans.
- Shorten cables going past fans so they cannot make contact.
- Check fan screws are tight and brackets secure.
- Enable fan stop features so fans disable when not needed.
Properly routing cables during build and doing periodic maintenance checks can prevent buzzing from fan interference.
Summary of Major Causes of Computer Humming Noise
Here is a summary of the most common components that can generate humming or buzzing noises in a desktop computer:
| Component | Potential Issue Causing Noise |
|---|---|
| Power Supply | Failing PSU fan, failing transformers/chokes, overloaded PSU |
| Cooling Fans | Bad fan bearings, imbalanced blades, loose fan brackets |
| Hard Drive | Failing drive motor, failed ball bearings, drive heads striking platters |
| Peripheral Cables | Electromagnetic interference noise leakage |
| Inductors/Coils | “Coil whine” vibration under system load |
| Loose Wiring | Cables touching and interfering with fan blades |
Conclusion
Humming or buzzing coming from a computer can be caused by a number of components such as cooling fans, hard drives, power supplies, interference from cables, or electrical noise from inductors. Troubleshooting involves isolating the location of noise and addressing any underlying hardware issues. Cleaning or replacing failing parts like power supplies and fans resolves many buzzing issues. Proper cable management ensures wires stay clear of fan blades. While noises can be annoying, identifying and addressing the cause is key to preventing performance issues or damage to components.