Why Xiaomi does not see the SIM- MTS card: from banal errors to hidden defects

You inserted the SIM- MTS card into the slot of the Xiaomi smartphone, but instead of the usual “strips” of the network, the screen flaunts the words “No services”, “SIM- card not detected” or even a void? The problem occurs both on budget Redmi and flagships Xiaomi 14 – and the reasons for it are dozens. From banal contamination of contacts to hardware malfunctions of the communication module.

In this article, we will look at all possible scenarios why Xiaomi does not see the SIM- MTS card, from user errors to factory defects. You will learn how to diagnose the problem yourself, which settings to check first, and when it is time to bring the phone to the service center. And for the most difficult cases, we have prepared a unique table of compatibility of Xiaomi models with MTS networks in the regions of Russia (relevant at 2026 year).

1 Card Check SIM- Card: 5 Steps Before Contacting the Service

Before disassembling your phone or resetting your settings, make sure that the problem is not with the SIM- card itself. The MTS operator regularly updates the card firmware, and physical wear and tear of contacts is one of the most common causes of problems.

• 🔄 Reboot your smartphone. Sometimes the system freezes when you initialize the communication module, just hold the power button for 10 seconds and turn the device on again.
• 📱 Check the card on another phone. If the MTS doesn't work there, either the operator or the SIM is having a problem. Try a friend's card on your Xiaomi.
• 🧹 Clear the contacts. Take an eraser or a microfiber, gently wipe the gold contacts on the SIM- card. Don't use alcohol or liquids!
• 🔧 Change the slot. If you have a Xiaomi with two slots (like the Redmi Note 12 Pro+), move the card to another slot.
• 📞 Call MTS Support. Dial *111# or 0890 from another phone and check if your SIM has been blocked for debts or suspicious activity.

If after these manipulations Xiaomi still does not see MTS, move to the next section. Important: do not try to insert the SIM- card "with force" - this can bend the slot contacts!

2. Network settings: what could have gone wrong in MIUI

MIUI is known for its "self-regulation" of network settings, especially after updates or factory resets.

1. Network Mode. Go to Settings → SIM- Cards and Mobile Networks → [Your SIM MTS] → Network Type. Make sure you select 4G (preferably) or 3G/2G (auto). If you only need a 2G, the smartphone will not be able to connect to modern MTS towers.
2. Roaming: Check if National Roaming is on on in the same menu, and without it, MTS may not be able to catch any connections in some regions (like Crimea, Kaliningrad).
3. APN- Profile. Dial ###4636##, select Phone Information and scroll to Setting up APN. Make sure that the profile is active on the Internet.mts.ru (for the Internet) and mms.mts.ru (for MMS).

If the settings are lost, you can reset them to factory: Settings → SIM- cards → [Your SIM] → Network reset. After that, the phone will restart and request PIN- code again.

Attention! ⚠️ If after discharge APN The problem remains, do not add profiles manually from the Internet – this can lead to blocking access to mobile data. It is better to request automatic settings from the MTS through USSD-team111*242#.

3. Hardware problems: from slot to antenna

If the software methods didn’t help, it could be the hardware. Here are the most vulnerable nodes in Xiaomi smartphones that affect the performance of the SIM- cards:

To diagnose a hardware problem, try inserting a SIM- card from another carrier (e.g., Tele2 or MegaFon). If Xiaomi doesn't see it, it's the phone. If it does, it's the MTS (locking, frequency incompatibility) problem.

Attention! ⚠️ Don't try to solder your contacts or clean the slot with alcohol - this can permanently put your phone out of action. Xiaomi service centers use an ultrasonic bath and specialized fluxes for such work.

4. Software failures: from firmware to viruses

MIUI firmware errors are a common cause of problems with SIM- cards, especially after airborne updates (OTA) or manual firmware through Fastboot.

• 📱 The phone sees the SIM- card, but does not catch the network (No services).
• 🔄 After the reboot, the problem temporarily disappears.
• 🛠️ In Settings → About the phone, the MIUI version is marked as "Unstable."
• 🦠 Antivirus finds suspicious files in /system/priv-app/TeleService.

How to fix it:

1. Reset network settings. Go to Settings → System → Reset settings → Network reset. This will delete all stored Wi-Fi and APN, but return factory modem settings.
2. Reverse Update. If the issue appears after the update, go to Settings → About Phone → System Update, click on the three dots at the top and select Remove the latest update.
3. Download the stable version of MIUI for your model from the official Xiaomi website and run through Recovery (instruction below).

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Before resetting your network settings, write down or photograph all the profiles saved by APN-. Once reset, you can manually restore them to Settings → Mobile Network → Access Points (APN).

For manual firmware through Recovery:

1. Download the firmware (.zip) for your model.


2. Rename the file to “update.zip” and place it in the root of the phone’s memory.




3. Turn off the phone, press Volume up + Power to enter Recovery.




4. Select Install update.zip to System and confirm.

Attention! ⚠️ Firmware through Fastboot (from PC) can lead to bootloader locking if not unlocked in advance via Mi Unlock Tool. On Xiaomi 13/14 models, unlocking takes up to 720 hours of waiting!

5. IMEI Block: Why MTS Can 'Block' Your Xiaomi

If your Xiaomi is bought abroad (especially in China), MTS may block access to the network because of the IMEI mismatch with the authorized device base, and this applies to phones with “gray” firmware, where the IMEI was changed.

How to check:

1. Dial *#06# and your IMEI (15 digits) will be displayed on the screen.
2. Check it out at IMEI.info. If the Blacklisted status is a blacklisted device.
3. Make sure that the first 8 digits (TAC- code) match your Xiaomi model. For example, for the Redmi Note 12 TAC starts with 8637... or 8695.

Decisions:

• 📄 Official unlock. If IMEI is clean but MTS is blocking access, contact the phone parlor with your passport and your phone purchase agreement.
• 🔧 Restore IMEI. On MediaTek models (e.g. Redmi 10C), you can restore the original IMEI via Engineer Mode (code ##3644633##). Qualcomm will require a PC and a program called QCN Rebuilder.
• ⚖️ Legal way: If the phone is bought in Russia, but MTS refuses to unlock, write a complaint to Roskomnadzor with reference to the law "On Communications" (Article 44, paragraph 5).

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If your Xiaomi IMEI starts with 00000000 or repeating digits, it is 100% a sign of a software failure or forgery.

6.Regional Limitations: Why MTS Doesn't Work in Your Xiaomi

Not all Xiaomi models support MTS frequencies in Russia, for example, the Chinese versions of the Redmi K50 or Xiaomi 12S Ultra do not support the B20 (800 MHz) and B3 (1800 MHz) bands that MTS actively uses in the regions.

Check the compatibility of your model:

If your model doesn’t support the desired frequencies, there are two options:

1. Buy a signal repeater (for example, Huawei B525) - it "translates" the signal to the MTS compatible frequencies.
2. Switch the global version of MIUI. Sometimes this will unlock hidden ranges (but it doesn't guarantee stable performance).

Attention! ⚠️ Before buying Xiaomi, check the frequency support on the FrequencyCheck website. For example, for MTS, B1 (2100 MHz), B3, B7 and B20 are critical.

7.When to contact the service: checklist before the visit

If you have tried all the methods in this article, but Xiaomi still does not see the SIM- MTS card, it is time to carry the phone for repair.

The cost of repairs in official Xiaomi services (data for 2026):

• 🔧 Replacement of SIM-slot: 1,200–2,000 ₽ (including work and detail).
• 📡 Repair of the antenna module: 2,500–4,000 ₽ (depending on model).
• 🔄 Reflashing with Refurbishment IMEI: 1,500–3,000 ₽.
• 🛠️ Motherboard replacement: 5,000-15,000 ₽ (on flagships like Xiaomi 14).

Beware of “artisanal” workshops that offer:

• ❌ "Swift IMEI in 5 minutes" is a scam, such IMEI will be blocked in a week.
• ❌ “Switch the modem chip to AliExpress” — after that, the phone will stop working at all.
• ❌ “Restor the slot with soldering” without diagnosis – often this leads to short circuit.

Tip: Before repairing, check the reviews on 2GIS or Yandex.Maps. Official Xiaomi partners are marked with the icon "Authorized Service Center".

FAQ: Frequent questions about problems with the SIM- MTS card in Xiaomi