Why does my SD card keeps mounting and unmounting?

Having an SD card that keeps mounting and unmounting can be very frustrating. This issue prevents you from reliably accessing the files stored on the card. There are several potential causes for this problem that are worth investigating.

Troubleshooting Steps

Here are some steps you can take to troubleshoot an SD card that keeps remounting:

  • Try the SD card in another device – Does the issue occur in other devices like a computer, camera, etc? If so, it points to a problem with the card rather than something specific to your current device.
  • Check the physical condition of the card – Inspect the SD card for any damage or corrosion on the metal contacts. Damaged pins can cause a loose connection resulting in mounting/unmounting.
  • Try a different SD card – Test with another known good SD card if possible. This can determine if the issue is with your current card or the device card reader/slot.
  • Update device drivers – Make sure you have the latest drivers installed for your device’s card reader. Outdated drivers can sometimes lead to connection problems.
  • Clean the SD card contacts – Use a clean pencil eraser to gently rub the metal pins to remove any corrosion or dirt buildup.
  • reformat the SD card – Reformatting fully resets the card which may resolve file system errors causing mounting issues.

Potential Causes

If the basic troubleshooting steps don’t fix your SD card mounting/unmounting issues, here are some common causes to consider:

SD Card Reader/Slot Hardware Issues

The SD card reader or slot hardware in your device could be damaged or worn out. Issues like loose/broken pins, dirt/dust buildup, and general wear over time can prevent a solid connection from being made with inserted cards. This interruptions in connectivity can lead to the appearance of repeated mounting and unmounting.

SD Card File System Errors

The file system on your SD card could have errors that prevent it from properly mounting. This is especially common with SD cards that have been used extensively and are older. File system damage can occur from things like improper ejection of the card, power interruptions, excessive heat, and general degradation over time with heavy usage. The card may need to be reformatted to fix file system issues.

SD Card is Failing or Damaged

If your SD card is very old or has been through a lot of read/write cycles, it may be reaching the end of its lifespan. Once SD cards start to fail, symptoms like repeated mounting/unmounting are common. Physically damaged cards that have been dropped, bent, or gotten wet can also exhibit similar connectivity problems. A failing or damaged SD card will need to be replaced.

Incompatible SD Card

Using an SD card that is incompatible with your device can potentially lead to connectivity issues. Make sure your card matches the specifications supported by your device – for example, SDHC vs SDXC cards or matching the speed class rating like Class 10 or UHS-1. An incompatible or lower class card may struggle to maintain a steady connection.

Insufficient Power Delivery

If your SD card requires more power than your device’s reader can provide, it may unmount itself repeatedly after short mounts due to power fluctuations. This is most common with high capacity cards or devices with lower powered card slots. You may be able to resolve this issue by using a lower capacity card that needs less power.

Card Reader Driver Issues

Problems with your computer or device’s SD card reader drivers can also cause connectivity issues leading to remounting behavior. Try updating your card reader drivers to the latest available version to rule out any driver-related problems.

Excessive Vibration

If your device and SD card are subjected to constant significant vibration, it can disrupt the physical connection between the card and reader. Make sure your device is mounted securely in a stable position without ongoing vibration. Consider attaching rubber dampeners if needed.

Fixing an Unmounting SD Card

If you’ve narrowed down the cause of your SD card unmounting issues, here are some tips for fixing the problem:

  • Replace a damaged or failed SD card
  • Reformat cards with file system errors
  • Clean SD card metal contacts
  • Update card reader drivers
  • Use a compatible SD card
  • Isolate device from vibration sources
  • Replace damaged card reader hardware

Reformatting the card or performing a full factory reset on your device can resolve software issues causing connectivity problems. Physical issues with the card or hardware may require replacement of the damaged components.

Preventing Future Mounting/Unmounting Issues

You can take proactive steps to prevent issues with your SD card unmounting itself in the future:

  • Eject the SD card properly before removing it
  • Be gentle when handling cards to avoid physical damage
  • Don’t expose cards to moisture, dust, or excessive heat/cold
  • Use high quality, name brand SD cards
  • Replace old or heavily used SD cards
  • Make sure your device is on a stable, vibration-free surface
  • Keep your device’s card reader slot clean and dust-free

When to Replace an SD Card

As a rule of thumb, you should replace an SD card that is showing mounting/unmounting issues in the following situations:

  • The card is 5 years old or older
  • You’ve written over 20,000 photos to the card
  • The card has visible damage or bent/corroded pins
  • You’ve reformatted the card multiple times without improvement
  • The card’s performance seems to be declining
  • The card was not designed for high endurance usage

Quality name brand SD cards used in optimal conditions can last for many years. But heavier usage, inadequate care, and old age can shorten useful lifespan. Remember to backup important data as cards start to fail.

SD Card Mounting and Unmounting FAQs

Why does my phone keep saying SD card unexpectedly removed?

This error message about the SD card being unexpectedly removed generally means there is some kind of connectivity issue between the card and your phone’s card reader. Potential causes include dirty contacts on the card, incompatible card types, a loose card reader, damaged card, reader hardware issues, or problems with the card’s file system.

How can I stop my SD card from unmounting?

To prevent your SD card from unmounting unexpectedly:

  • Clean the card’s metal contacts
  • Make sure the card is properly seated in the card reader
  • Check for issues with vibration or inadequate power delivery
  • Replace damaged or incompatible cards
  • Update the card reader drivers

Why does my SD card keep disconnecting?

Frequent disconnection of your SD card is also generally caused by an intermittent connection. This can be due to physical damage, corrupted data, incompatible cards, power delivery issues, card reader problems, vibration, outdated drivers, or normal wear over time degrading connectivity.

How do I stop my phone from repeatedly mounting SD card?

Tips for stopping your phone repeatedly mounting the SD card include:

  • Cleaning the SD card metal pins
  • Replacing old, damaged, or incompatible SD cards
  • Updating device drivers and firmware
  • Ensuring the card slot/reader is clean and undamaged
  • Making sure the device is on a stable surface free of vibration
  • Checking for issues with inadequate power to the SD card

Why won’t my phone read my SD card?

If your phone won’t read your SD card, possible causes include:

  • The card is not properly inserted or is loose
  • The card has become corrupted or the file system damaged
  • The contacts on the card are dirty or damaged
  • The card is an incompatible type for your device
  • There are issues with the SD card reader hardware/drivers
  • The card is too old and has failed

Carefully reinserting the card, cleaning the contacts, reformatting the card, updating device software/drivers, or replacing the SD card may resolve reading issues.


SD cards randomly mounting and unmounting can certainly be annoying. But in most cases this issue can be fixed by basic troubleshooting steps. The most common solutions are replacing worn-out cards, updating device drivers, reformatting the card, correcting any physical connection problems, and isolating the device from excess vibration. With software-based fixes and improved handling practices, you can get back to reliably using your SD storage.

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