How to know if a memory card works on a Xiaomi phone: a full check

Have you inserted a memory card into Xiaomi but aren’t sure if your smartphone recognizes it? or suspect that the micro-SD is not working properly but you don’t know how to check it? In this article, we’ll look at all the diagnostic methods, from basic to advanced, that will help identify storage problems on any Xiaomi device (including Redmi, POCO and Black Shark).

Memory cards are one of the most vulnerable components of a smartphone, and they can fail due to physical damage, file system errors, or firmware incompatibility, and the symptoms of a malfunction are not always obvious: sometimes the card is detected by the system but does not write files, and sometimes it simply disappears from the storage menu after rebooting, and we will show you how to check the performance at all levels, from display in settings to testing the read/write speed.

We will pay special attention to typical errors of Xiaomi users, for example, when the card is formatted as internal memory, but then ceases to be recognized, or when the smartphone “does not see” the drive after the MIUI update. All instructions are relevant for devices on MIUI 12/13/14 and HyperOS, including the latest models of 2026.

1. Basic check: is the card visible in Xiaomi settings

The first and easiest way is to check if the memory card is displayed in the storage menu.

1. Open the Settings → Storage.
2. Scroll down to the Port. Storage block (or «SD-map»).
3. If the map is defined, you will see its volume, occupied space and the Extract button.

If the Port. Storage section is missing, this may mean:

• 🔌 The card is not inserted or inserted incorrectly (check the tray).
• 🚫 The slot for the memory card is damaged (relevant for models with a hybrid slot, for example, Xiaomi). 12T).
• 🔄 The card is incompatible with the device (e.g. exFAT on older smartphones).
• 🛠️ Formatting is required (the system does not recognize the file system).

In some models (for example, POCO F5 Or the Redmi Note 12 Pro.+) The card may be displayed in the storage menu, but not available for recording, in which case there will be an icon next to its name. ⚠️ and the inscription "Reading only" or "Damaged».

2. Checking through "My Files": Are files available

Even if the card is displayed in the settings, it doesn't guarantee that it's fully functional, for example, it can be recognized by the system, but it doesn't allow you to write data or open files.

1. Open the My Files app (or any other file manager).
2. Go to section. SD-map or port.
3. Try to open any file (photo, video, document).
4. Create a new folder or copy a file from internal memory.

If files are opened but new data is not written, the problem may be:

• 🔒 Write protection (check the switch on the card adapter).
• 📁 Damaged file system (requires formatting).
• 📱 Restrictions MIUI (For example, the card is formatted as internal memory, but the settings are reset).

⚠️ Note: If the card is displayed as internal memory but does not write files, do not remove it without first unmounting in the settings!

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On some Xiaomi models (e.g. Redmi 10C), the memory card may “disappear” after the MIUI update. In this case, rebooting or resetting the Storage app settings (Settings → Applications → App Management → Storage → Reset) will help.

Read/write speed test: performance diagnostics

Slow memory card performance is a common problem, especially on Xiaomi’s budget models. If files are copied too long or 4K video is slow to write, it’s worth checking the drive speed.

1. Install the A1 SD Bench app (free on Google Play).
2. Choose yours. SD-map.
3. Run the Read and Write test.

Compare the results with the card’s claimed characteristics (usually shown on the package or in the model name, such as the SanDisk Ultra A1 or Samsung EVO Plus U3).

If the actual speeds are significantly lower than the stated speeds (for example, U3 shows 5 MB/s instead of 30), this may indicate:

• 🛒 Counterfeiting (especially relevant for cheap cards on AliExpress).
• 🔋 Wear of memory cells (if the card is old and actively used).
• 📱 Slot restrictions (some Xiaomi models, such as Redmi) 9A, supportive UHS-II).

4. Checking for File System Errors

If the memory card is detected but is not stable (for example, files are lost or corrupted), the problem may lie in file system errors. Xiaomi has a built-in tool to check:

1. Go to Settings → Storage → Port. storage.
2. Click on the three dots in the top right corner and select “Storage settings”.
3. Tap “Format” (if the option is active) or “Error Check” (on some firmware).

If there is no built-in tool, use the PC:

1. Connect the card to the computer through the card reader.
2. Open "This Computer"** (Windows), find a removable disk.
3. Right-click → “Properties” → “Service” → “Error Check”.

If the checker finds errors but can't fix them, you'll have to format the map. Importantly, formatting will delete all the data! If there are important files on the map, try to restore them first with programs like Recuva or DiskDigger.

⚠️ Note: If the card is formatted as internal memory in Xiaomi settings, it cannot be checked on a PC – the system simply will not see it as a removable disk. MIUI.

Diagnosis of physical injuries

Memory cards often fail due to mechanical damage, such as falls, moisture or overheating.

• 🔥 The phone overheats when working with the card.
• 🔄 The map is disconnected and appears again.
• 🚫 The card's contacts have blackened or bent.
• 💧 The map shows traces of oxidation or moisture.

To check the card for physical defects:

1. Remove the card and inspect its contacts (should be clean, without scratches).
2. Try inserting it into another phone or card reader.
3. If the card is not detected in any device, it is likely dead.

On some Xiaomi models (e.g. Xiaomi 13 Ultra), the memory card slot is combined with a SIM tray. If the mobile connection stopped working after inserting the card, the contact mechanism of the slot may be damaged, in which case repair is required at the service center.

Try to clean contacts with alcohol|Check the card in another device|Do not heat or cool the card (this will aggravate damage)|If the map is not read, contact the data recovery laboratory.-->

6.Firmware and MIUI problems: when software is to blame

Sometimes the memory card stops working after updating the MIUI or resetting the settings.

• 🔄 The card is determined after the reboot, but disappears after a few minutes.
• 📱 The settings display the wrong volume (for example, 16 GB instead of 128 GB).
• 🚫 When trying to format, an error appears: “Team is unacceptable»**.

Solutions to programmatic problems:

1. Resetting the settings of the application "Storage"**:
2. Cleaning up the MIUI cache: Settings → About the phone → Memory → Clean up the cache
3. Rejection of the MIUI update (if the problem appears after the update).

If nothing helps, try flashing your phone again through the Mi Flash Tool (instructions are available on the official Xiaomi website). In extreme cases, you may need to unlock the bootloader and install custom firmware (for example, Pixel Experience), but this will void the warranty.

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If the memory card stopped working after the MIUI update, try resetting the Storage app first, which solves the problem 70% of the time without complex manipulation.

7. Alternative Verification Methods (for experienced users)

If standard methods don't work, you can use advanced diagnostic tools, which require root rights or a PC connection.

Method 1: Checking with ADB

Connect your phone to your PC, enable debugging over USB and execute the command:

adb shell sm list-disks

If the card is defined, you will see a string like disk:179,XX. Then check its state:

adb shell sm partition disk:179,XX private

Method 2: Testing with CrystalDiskMark (on PC)

• Connect the card to the computer through the card reader.
• Run CrystalDiskMark and select your removable drive.
• Test 4K Q32T1 (will show the real speed when recorded randomly).

Method 3: Verification SMART-data (only for data purposes) USB-cardreader)

Use H2testw (Windows) or F3 (Linux/macOS) to check the real size of the map and search for broken sectors, and these tools will help you identify fakes where the real volume is less than claimed.

⚠️ Attention: Use ADB And other low-level tools can cause data loss or firmware damage. If you're not sure what you're doing, you should contact a service center.

FAQ: Frequent questions about memory cards in Xiaomi