How to check the communication module on Xiaomi: from diagnosis to repair

The communication module is the “heart” of your Xiaomi’s wireless features, responsible for mobile internet, calls, Wi-Fi, Bluetooth and even mobile internet. GPS. If the smartphone suddenly stopped catching the network, loses the connection or gives errors such as «SIM-No map detected, and that's the component that's most often the problem, but how do you tell a software failure from a hardware failure? In this article, we’ll break down 5 working methods of checking, including hidden engineering menus, test commands, and third-party utilities – without having to contact a service center.

It is important to understand: the symptoms of a “dying” communication module may be masked as problems with firmware or SIM-For example, if you update the card after the update MIUI The mobile network is gone, but the Wi-Fi is stable, and it's the software, not the hardware. SIM-The card, which is not connected to the router and does not find other devices via Bluetooth, is a direct sign of a hardware malfunction.

Signs of failure of the communication module

Before you rush to test your smartphone, check if your symptoms are actually indicative of a communication module, and here are the key “bells” that should alert you:

• 📵 There is no mobile network: the smartphone does not catch any SIM-card (even after rebooting), or network indicator shows “No service».
• 🔄 Continuous reconnection: 4G/5G It appears, then disappears, and in the status bar flashes the icon of data transfer.
• 📶 Weak signal: even in the zone of confident coverage, the smartphone shows 1-2 “sticks”, while other devices catch a full signal.
• 🔌 Problems with Wi-Fi/Bluetooth: Does not connect to networks, loses connection, or other devices do not see your Xiaomi when searching.
• 📍 GPS not working: maps determine location with a large error or do not find satellites at all.

If 2-3 items from the list match your situation, it's likely a problem in the communication module. But don't panic: sometimes it's firmware, settings, or even mechanical damage (for example, oxidation of contacts). SIM-map).

⚠️ Warning: If the smartphone stopped seeing the network after falling, getting moisture or disassembling yourself - do not waste time on diagnosis. Immediately bring to the service: most likely, the plume has departed or the board is damaged.

Method 1: Checking through the engineering menu (codes ##)

The fastest way to assess the status of the communication module is to use hidden test menus, which are on all Xiaomi smartphones, but the paths to these differ depending on the model and version. MIUI. We will look at universal commands that work on 90% of devices.

Open the Phone app and enter the following combinations:

• 📱 General information about the network: ##4636## → Select "Phone Information." This shows the mobile network data, IMEI status SIM-map.
• 🔍 Radio module test: ##6484## (or #64663## on new models.
• 📡 Wi-Fi: ##232338## - shows MAC-address and current status of the module.
• 🔄 Bluetooth Test: #232331## – Checks the availability of the module and its version.

If nothing happens after entering the code, then the menu is blocked by the manufacturer (relevant for some Redmi models and the product). POCO After the updates, then proceed to the next method.

⚠️ Note: On some Xiaomi models (e.g. Redmi Note 10 Pro or Mi 11), the engineering menu may require root permission. If the message “Server communication is impossible” appears after entering the code, use alternative methods from this article.

Method 2: Diagnosis through the application "Equipment Test» (MIUI Hidden Settings)

If the engineering codes don’t work, use the built-in Equipment Test app (or MIUI Hidden Settings. It's on all Xiaomi smartphones, but it's hidden from the user:

1. Go to Settings. → The phone.
2. Click 5-7 times in a row on the line Version MIUI (A message will appear saying, “You’ve become a developer»).
3. Return to the main settings menu and open Additional → for developers.
4. Find the Equipment Test (or Diagnostic on global firmware).

In the test menu, select:

• 📶 Mobile network – module verification 4G/5G and SIM-map.
• 📶 Wi-Fi – Test of speed and stability of connection.
• 🔵 Bluetooth – Checking for Device Detection.
• 📍 GPS — satellite search and coordinate accuracy.

If the test results show a red cross or Fail reading next to a module, it confirms a hardware malfunction. The green ticks (Pass) indicate that the module is functional and the problem lies in the settings or firmware.

Try another one. SIM-map|Reset the network settings|Update firmware|Check the contacts SIM-oxidation|Contact the service center-->

Method 3: Verification IMEI and the status of the module through ADB

If standard methods have not yielded results, you can delve into the diagnosis with the help of ADB (Android Debug Bridge. This is a way for power users and requires a computer. Here's a step-by-step guide:

1. Download and install Platform Tools (includes adb).
2. Turn on the smartphone debugging by USB (Settings → For developers).
3. Connect Xiaomi to your PC and open the command line in the adb folder.
4. Enter a command to check. IMEI: adb shell service call iphonesubinfo 3 If IMEI Displayed as null or unknown – the communication module is faulty or disabled.
5. Check the status of the radio module: adb shell dumpsys telephony.registry Search for the lines mServiceState=0 (no network) or mSignalStrength (signal level).

If the commands return errors or empty values, this may indicate:

• 🔌 Lack of communication between the processor and the module (problem with the plume).
• 🔧 Damage to the module firmware (solved by flashing the).
• 💥 Hardware failure (requires a replacement module).

⚠️ Note: If you have never worked with ADB, Incorrect commands can cause system failure or data loss.

💡

Before use ADB Backup your data through Settings → Additionally. → Backup. This will keep you from losing contacts and photos when you crash.

Method 4: Testing with Third-Party Applications

If you don’t want to go through the engineering menu or ADB, You can use specialized applications that automate the test and give you clear results.-3 utility for Xiaomi:

• 📊 Network Signal Info – shows the signal level of the mobile network, Wi-Fi and Bluetooth in real time, useful for detecting “failures” of communication.
• 🔍 Phone INFO ★Samsung★ (works on Xiaomi too – displays detailed information about the communication module, IMEI, operator database.
• 📡 GPS Status & Toolbox – Testing the Work GPS, The number of satellites found and the coordinate accuracy.

How to use:

1. Install the app from Google Play.
2. Run a test of the appropriate module (such as Wi-Fi or Mobile Network).
3. Compare the results with reference values (usually given in the appendix help).

Example: Network Signal Info signal level 4G should be no lower -100 dBm, if the value is worse -110 dBm is a sign of problems with an antenna or module.

Method 5: Visual inspection and contact check

If all the software tests were successful, but the problems remained, it was time to look inside the smartphone.

• 🔌 Oxidized contacts SIM-cards (especially if the smartphone has been in a wet environment).
• 📶 Damaged antenna plumes (for example, after falling).
• 🔋 A bloated battery that presses on the board and disrupts the connection.

For inspection:

1. Turn off your smartphone and remove the tray. SIM-map.
2. Check the contacts for oxidation or contamination (clean with alcohol if necessary).
3. If you have experience disassembling – remove the back cover and inspect the plumes going to the communication module (usually located near the top of the board).

🔹 Signs of hardware breakdown:

• Darkened or burned tracks on the board.
• Torn or bent contacts of plumes.
• Corrosion traces around the communications module.

⚠️ Attention: If you are not sure about your skills, do not disassemble the smartphone yourself. Xiaomi uses fragile plumes that are easy to damage.

What to do if the communication module is faulty?

If the diagnosis confirmed the problem with the module, you have 3 options for the development of events:

🔹 If you decide to repair yourself:

1. Buy the original communication module for your model (for example, on AliExpress or in specialty stores).
2. Use a hair dryer or soldering station - the module is soldered to the board.
3. After the replacement, check. IMEI (If he has fallen, restore through MTK Engineering Mode or Service Center).

🔹 If you're on service:

• Check if they give a job guarantee.
• Ask to keep it. IMEI (Otherwise, the smartphone will become a “brick” without a network).
• Ask if they will use the original module or analogue.

💡

If the communication module is replaced IMEI — The smartphone will not work in the networks of operators, and it can be restored only through specialized software (for example, Maui). META for MediaTek chips or QCN for Qualcomm).

FAQ: Frequent questions about Xiaomi communication module