How can I check the possible cause ‘USB power management’?

If there is no change in the first step, compare the steps in order, up to ‘Completely shut down the PC and turn it back on.’ If symptoms disappear immediately after certain actions or the conditions for their occurrence change, this can be an important clue in narrowing down the cause.

External hard drive keeps disconnecting while in use: When do I need a professional inspection?

Even if you follow the above solution steps in order, if the external hard drive keeps disconnecting, or hardware abnormal signals such as a burning smell, abnormal noise, overheating, or failure to recognize parts appear, we recommend backing up important data and having a professional inspection.

PC FIX

Computer Troubleshooting Guide

Storage

External hard drive keeps disconnecting while in use

Q: What should I check first if my external hard drive keeps disconnecting?

First, proceed with the ‘Unplug the USB device and connect it directly to another port’ step. Quickly isolate issues between the device itself and specific ports and hubs. We recommend that you avoid changing multiple settings at once and check to see if your symptoms change after each step.

If you see the symptom of “external hard drive keeps disconnecting”, possible causes include USB power management, cable/hub issues, etc. Cross-test devices, cables, and USB ports and check for power management and driver issues.

Solving Order
We've organized the methods starting with the simplest and least expensive ones. Please check the solutions one by one, starting from the top.

Do you have these symptoms?

External hard drive keeps disconnecting
Disconnect external SSD
USB storage device disconnected

main causes

USB power management
Cable/Hub Problems
drive error

How to solve

Please check them in order from the top. If the issue is resolved, you do not need to proceed to the next step.

Unplugging the USB device and connecting it directly to another port

Quickly isolate issues between the device itself and specific ports and hubs.

Difficulty Easy time 3-5 minutes cost 0 won

1If you are using a USB hub, remove it and connect it directly to your PC.
2Connect to a different USB port.
3If your device has replaceable cables, use a different cable.

confirmation point

After these steps, check if the “external hard drive keeps disconnecting” symptom decreases or disappears. If there is no change, also check the possibility of USB power management in the next step.

Shut down your PC completely and turn it back on

This can reset a USB controller that has temporarily stopped responding.

Difficulty Easy time 3 minutes cost 0 won

1Shut down your PC.
2For desktops, briefly disconnect the power cable and for laptops, unplug peripherals.
3Turn it on again after 30 seconds to 1 minute.

Check USB errors in Device Manager

You can check driver/device status such as Code 43/unknown device.

Difficulty Moderate time 10-20 minutes cost 0 won

1Open Device Manager.
2Check the Universal Serial Bus controller and the problem device.
3If there is a warning icon, remove the device and reboot or update the driver.

Check USB power saving settings

Due to the power saving policy, the device may turn off and reconnect during use.

Difficulty Moderate time 10 minutes cost 0 won

1Check the USB Selective Sleep setting in Power Options.
2In Device Manager, try turning off the USB hub's power plan for diagnostic purposes.

Update or reinstall chipset/USB drivers

Outdated or corrupted chipset/USB drivers may be causing the symptom.

Difficulty Moderate time 10~30 minutes cost 0 won

1Check the device in Device Manager.
2Check your PC or component manufacturer's site for chipset/USB drivers for your current model.
3If the problem started immediately after an update, consider rolling back to the previous stable version.
4After installing the driver, restart your PC.

Test your device on another PC

If the same symptom occurs on another PC, the USB device itself is likely to be malfunctioning.

Difficulty Moderate time 10 minutes cost 0 won

1Connect your device to another PC.
2If the symptoms are the same, consider manufacturer diagnosis/firmware/replacement.

Frequently Asked Questions

We've put together a list of things we frequently check regarding this issue.

Related issues

If the symptoms do not match exactly, please check the issue below.

Peripherals

USB device keeps connecting and disconnecting

When troubleshooting a USB device that keeps connecting and disconnecting, it is important to rule out the causes one at a time. Based on the “USB keeps disconnecting” symptom, check USB power management, hub/cable, and proceed to the next step. Cross-test devices, cables, and USB ports and check for power management and driver issues.

View solutions →

Peripherals

This is a USB 3.x device, but the transfer speed is very slow.

This guide is designed to classify USB 2.0 port/cable and hub restrictions in a safe order in “USB 3.0 slow” situations. Cross-test devices, cables, and USB ports and check for power management and driver issues.

View solutions →

Peripherals

USB Code 43 error appears in device manager

If the current symptom is close to “USB code 43,” first check for device firmware/driver errors, port power, or cable problems. Cross-test devices, cables, and USB ports and check for power management and driver issues.

View solutions →

Peripherals

Devices connected to a USB hub are unstable.

If “USB hub disconnection” repeats, it is better to narrow the scope to hub power shortage and bandwidth/cable limitations rather than changing several settings at once. Cross-test devices, cables, and USB ports and check for power management and driver issues.

View solutions →

Look for other symptoms too

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