What to do when external hard disk is not detected?

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What to do when external hard disk is not detected

It can be frustrating when you plug in an external hard drive and it is not detected by your computer. There are a number of potential causes for an external hard drive not being detected, but the good news is that there are also a number of solutions you can try to fix the issue.

Quick Diagnosis

As a first step, check the basics to diagnose why your external hard drive is not being detected:

  • Make sure the USB cable is securely plugged into both the drive and the computer.
  • Try plugging the cable into a different USB port on your computer.
  • Check if the external drive is receiving power and is turned on.
  • Try connecting the external drive to a different computer.
  • For desktops, switch out the USB cable and try other USB ports on the back of the tower.

Often, the issue is simply a loose connection or damaged cable that is preventing the computer from detecting the external drive. Reconnecting the drive with a new cable will frequently fix the problem.

Update Drivers

If the quick diagnosis does not reveal the issue, the next thing to check is whether you have the latest drivers installed for the external drive. Outdated, corrupt, or missing drivers can result in external hard drives not being detected properly by your computer.

To update your drivers, first identify the make and model of your external hard drive. Then go to the manufacturer’s website and check for the latest drivers available for that hardware. Download and install those drivers onto your computer.

For Windows computers, you can also open the Device Manager utility and check for any devices with yellow exclamation icons, which indicates a driver issue. Updating the drivers for that device may resolve your external drive detection issue.

Change Drive Letter

If your computer is detecting the external hard drive, but it is not showing up in your File Explorer, the issue may be due to drive letter conflicts. Here’s how to check and change the drive letter assignment in Windows:

  1. Open Disk Management (press Windows Key + R and type “diskmgmt.msc”).
  2. Locate your external drive in the disk list.
  3. If the drive doesn’t have a drive letter assigned, right-click it and select Change Drive Letter and Paths.
  4. Assign a new drive letter from the dropdown.
  5. Click OK to save the changes.

This will assign a drive letter to your external drive and should make it accessible in File Explorer.

Check for Errors

If your external hard drive keeps disappearing and reappearing unpredictably on your computer, there may be errors on the drive that are causing connectivity issues. You can scan for and repair errors using the CHKDSK utility.

To run CHKDSK on an external drive in Windows:

  1. Open an elevated Command Prompt window.
  2. Type “chkdsk X: /f” (replace X with your external drive letter).
  3. Press Enter and wait for the process to complete.
  4. Type “Y” if prompted to fix file system errors.
  5. Restart your computer when done and reconnect external drive.

CHKDSK will go through and scan your drive for file system errors, bad sectors, and data corruption, attempting to repair any issues found.

Initialize Disk

If your drive is brand new or completely blank, it may need to be initialized before it can be detected and accessed on your computer:

  1. Open Disk Management.
  2. Find your external drive and right click it.
  3. Select Initialize Disk from the menu.
  4. Select a partition style – MBR or GPT – and click OK.

This will initialize the drive and make it visible/accessible to your system. Then you can format the drive and begin using it as needed.

Format Drive

If initializing does not work, the next step would be to format your external hard drive to resolve detection and file system issues:

  1. Open Disk Management.
  2. Right click your external drive and select Format…
  3. Choose a file system – exFAT is recommended for external drives.
  4. Give your drive a new name if desired.
  5. Check Perform a quick format for faster formatting.
  6. Click OK to begin formatting.

Formatting will wipe all data on the external drive and reconfigure the file system, which often resolves many connectivity problems.

Test with Another Enclosure

In some cases, the issue could originate from a damaged enclosure rather than the hard drive itself. Testing the drive in a new external enclosure can help determine if the USB bridge or connector is faulty:

  1. Carefully remove the hard drive from its enclosure.
  2. Connect the hard drive to a new USB enclosure.
  3. Connect enclosure to your computer and check if drive is detected.

If the drive works in the new enclosure, then the original casing likely had a hardware issue. If drive is still not detected, then the hard drive itself is probably damaged or defective.

Replace USB Bridge

As an alternative to getting a completely new enclosure, you may be able to just replace the USB bridge board inside the case. This circuit board is what allows the SATA hard drive to communicate with your computer:

  1. Open enclosure and remove USB bridge board.
  2. Purchase replacement bridge board online.
  3. Install new bridge board in enclosure.
  4. Reassemble enclosure and reconnect drive.

Swapping out the USB bridge can help isolate and fix connectivity problems with a malfunctioning bridge board.

Connect SATA Directly

To rule out any USB related issues, you can remove the hard drive from the external enclosure and connect it directly to a SATA port on your computer’s motherboard:

  1. Open enclosure and extract SATA hard drive.
  2. Power off computer and open case.
  3. Connect the hard drive’s SATA connector directly to SATA port.
  4. Boot up PC and check if drive is recognized in BIOS/UEFI.

This allows you to bypass any USB connectivity issues and directly test SATA communication with the drive.

Special Cases

Here are some tips for troubleshooting detection issues on specific drive types:

External SSD Not Detected

For external solid state drives (SSDs), make sure TRIM is enabled:

  • Open Command Prompt as admin.
  • Type “fsutil behavior query DisableDeleteNotify”
  • If value is 0, TRIM is enabled. If 1, type “fsutil behavior set DisableDeleteNotify 0” to enable TRIM.

WD External Hard Drive Not Showing Up

For Western Digital drives:

  • Make sure the WD SmartWare software is installed.
  • Update drivers for WD external drive utilities.
  • Go to WD support site for help with WD product issues.

Seagate External Hard Drive Not Detected

For Seagate drives:

  • Confirm the drive LED is illuminating.
  • Use Seatools Windows installer to test and fix drive issues.
  • Contact Seagate support for further assistance.

Reset Drive

Resetting the external hard drive can help clear up any software related issues that could be preventing detection:

  1. With the drive connected, go to Device Manager.
  2. Right click on the external drive and select Uninstall device.
  3. Unplug USB cable and power off the drive.
  4. Wait 1 minute then reconnect the drive.
  5. This will reinstall the drivers and often resolves detection issues.

Clean Disk Contacts

Dirty or damaged contacts on the USB cable, enclosure, or hard drive itself can obstruct communication and result in the drive not showing up properly.

Carefully clean the following with a fiber cloth or soft brush:

  • External hard drive USB connector pins.
  • USB port connectors inside the external enclosure.
  • USB cable plug contact pins.
  • Motherboard USB port connector pins.

Cleaning drive and port contacts can help improve connectivity and get your drive recognized again.

Try a Different Computer

Connecting your external drive to another computer is one of the quickest ways to determine if the issue stems from the drive itself, or your computer.

If the drive fails to be detected by multiple computers, then the drive itself has failed or has an internal hardware problem. At this point, you will need to either replace the enclosure or consult a data recovery service.

However, if the drive is detected on other computers but not your own, the issue likely lies with your system’s USB ports, drivers, or other configuration problems.

Conclusion

External hard drives occasionally fail to be detected due to hardware faults, driver errors, drive letter conflicts, file system issues, or other problems. However, there are a number of troubleshooting steps you can take to diagnose and resolve most detection problems:

  • Check cable connections and try different ports/cables.
  • Update USB and motherboard drivers.
  • Change the drive letter assignment.
  • Check for disk errors and reformat if necessary.
  • Test the drive in a new enclosure or connect directly via SATA.
  • Reset the drive and clean the disk and port contacts.

Following these steps sequentially can help identify the underlying cause and get your external hard drive back up and running properly again. Contact the manufacturer for hardware-specific troubleshooting help when needed. In some cases, you may need to consult a data recovery service to retrieve data from a damaged external drive.