How to open a memory card on Xiaomi Redmi 4X: from connection to error elimination

Xiaomi Redmi 4X (codename Santoni) is still a popular budget smartphone, but many users face problems when working with microSD cards. The device does not see the drive, then the files are not copied, then the system asks you to format the card. In this article, we will analyze all the ways to connect and open a memory card on Redmi 4X – from the basic installation to solving complex errors.

Feature of the model – support for microSD up to 128 GB (officially) and a hybrid slot, which is shared with the user. SIM-This means that you have to sacrifice a second SIM to use the flash drive, but even after you physically install the card, you have to initialize it correctly in the system, otherwise the smartphone will not see the new files.

We analyzed the unique features of MIUI 8-12 firmware for Redmi 4X that affect external drives, and collected proven solutions. If your card is defined as “damaged” or your smartphone “can’t see” it, here you will find the answer.

1. Physical Memory Card Installation in Redmi 4X

Before you set up the software, make sure the microSD card is inserted correctly into the slot. The Redmi 4X has a hybrid tray: it combines space for the second nano-SIM and microSD. This means that you can not use two SIMs and a flash drive at the same time.

To insert a memory card:

• 📱 Turn off your smartphone (required!) or you risk damaging your tray contacts).
• 🔧 Take a paper clip or a special key from the kit, insert a tray into the hole (located on the left end).
• 💾 Take the tray out carefully. It has tags on it: SIM 2 or microSD. Insert the memory card with gold contacts down until clicking.
• 🔄 Put the tray back in place and turn on the phone.

⚠️ Note: Do not use memory cards with adapters SD→microSDs often don't fit in the tray or damage contacts. UHS-I (U1/U3).

Once turned on, the smartphone should automatically identify a new drive. If this does not happen, move to the next section.

2. Memory card setup in MIUI: formatting and mounting

If Redmi 4X saw a card but couldn’t open it, it’s probably a problem in the file system.The smartphone only supports FAT32 and exFAT (starting with MIUI 9). If your flash drive is formatted in NTFS or ext4, it’ll have to be reformatted.

How to do this:

1. Go to Settings. → Warehouse.
2. Tap on the name of your memory card (for example, SD-map: 32 GB).
3. Select Format → Format as internal (if you want to use a flash drive as part of your main memory) or Format as portable (for normal file storage).
4. Confirm the action. It'll take 1-3 minutes.

If the card still doesn't open after formatting, check it on another device (for example, on a PC through a card reader), possibly the drive is physically damaged.

Make sure the card is compatible (up to 128GB, 10/U1)

Format it to FAT32/exFAT on PC (if MIUI refuses to do so)

Check the contacts of the tray for pollution

Update the firmware to the latest version MIUI-->

3. Why Redmi? 4X Can't see the memory card: top-5 cause

If a smartphone persists in not recognizing microSD, the reasons may be hardware or software.

• 🚫 Incompatible file system: The card is formatted into NTFS or ext4. Solution: reformatting into FAT32 PC.
• 🔌 Tray problems: Contacts are contaminated or bent. Solution: clean with alcohol, gently correct contacts.
• 📱 Outdated firmware: B MIUI 8 were bugs with exFAT support.Solution: Update to MIUI 9+.
• 💾 Damaged card: Bad sectors or controller failure Solution: Check on PC with CrystalDiskInfo utility.
• 🔒 Write protection: The map has a physical lock switch on. Solution: Move the slider to Unlock position.

Especially frequent users of Redmi 4X fall into error "SD-The card is damaged. Try formatting it:

• The map was retrieved during the recording of data.
• The file system is damaged due to power failure.
• The drive is fake (especially relevant for "Chinese" flash drives on AliExpress).

⚠️ Note: If the card is defined as 0 MB or an unknown volume, the controller is likely to have failed, and only through specialized services (e.g., specialized services) can the data be recovered, PC-3000).

4. How to make a memory card the main storage (Adoptable Storage)

Adoptable Storage allows microSD to be used as part of internal memory, which is useful if Redmi 4X runs out of application space.

• ✅ Applications can be transferred to the map.
• ✅ Files are encrypted (more secure when stealing your phone).
• ❌ The card cannot be removed without a complete reset.
• ❌ Speed is lower than that of the built-in eMMC memory.

To activate Adoptable Storage:

1. Put the card in your smartphone.
2. Go to Settings. → Warehouse → SD-map.
3. Tap three dots (⋮) → Settings → Formatting as an internal.
4. Follow the instructions on the screen. Once formatted, the map will become part of the system.

Important: after this operation, all the data on the map will be deleted. Copy important files on your PC in advance.

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If, after formatting as internal memory, applications are still not ported to the map, try manually specifying the installation path in Settings → Applications → Default Installation.

5. Transfer data and applications to a memory card

Even if a card is defined as portable, you can transfer individual files and some applications to it. Here's how to do this:

File transfer (photo, video, music):

• 📁 Open Files (File Manager).
• 🔍 Find a folder with the necessary data (for example, DCIM photo).
• 📋 Select files, tap Move and select a memory card.

Portability of annexes:

1. Go to Settings → Applications.
2. Select the app you want (such as WhatsApp).
3. Slip the vault. → Change. → SD-map.
4. Confirm the transfer. Some system applications cannot be moved.

Note that not all programs support external memory, such as Facebook or Instagram, which may not be able to start after a transfer.

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On Redmi 4X, you can not transfer applications that have been installed as system (for example, pre-installed Xiaomi services) to the memory card.

6 Solving Memory Card Reading Errors

If the card is detected, but the files do not open or errors like “Can not mount” appear SD-Map, try these methods:

Method 1: Reboot the smartphone

Sometimes MIUI forgets to mount the card after an upgrade or prolonged use. Just reboot the Redmi 4X, which helps in 30% of cases.

Method 2: Cleaning the cache

1. Go to Settings → Applications → All applications.
2. Find a Storage or Media Storage.
3. Tap Clear the cache and Clear the data.
4. Reboot the phone.

Method 3: Testing for viruses

Some malware blocks access to external drives. Scan the map through Google Play Protection or Dr.Web.

Method 4: Resetting storage settings

If nothing helps, reset your storage settings:

Settings → Additional → Resetting settings → Resetting application settings →

This won't delete your data, but it will return the storage settings to factory settings.

7. Alternative ways to work with a memory card

If Redmi 4X is reluctant to recognize microSD, you can use external solutions:

• 🖥️ OTG-Adapter: Connect the card reader through USB-OTG And you can use the flash drive as an external drive.
• ☁️ Cloud Storage: Upload files to Google Drive or Mi Cloud and then download them to your phone. Suitable for a temporary solution.
• 🔄 Replacement tray: If contacts are damaged, buy a new tray for Redmi 4X (worth ~300-500 rubles. The replacement takes 5 minutes.

For advanced users, there is another option - manual mounting via ADB. This will help if the card is determined in fastboot, but not mounted in the system:

adb shell


sm list-disks




sm partition disk:179,64 private

Here, 179.64 is your card ID (learn it by sm list-disks), which requires an unlocked bootloader and root rights.

FAQ: Frequent questions about memory cards on Redmi 4X