Why Xiaomi’s second Bluetooth headphone doesn’t connect: A complete guide to diagnostics and repair

Did you pull Xiaomi Redmi AirDots or Mi True Wireless Earbuds out of your case, but one of them stubbornly refuses to connect? TWS-Headphones: the left or right module is not detected by the phone, flashes red, emits error beeps or simply stays silent, and the causes can be in software failures and hardware malfunctions, from a dead battery to damage to contacts in the case.

In this article, we’ll look at all the possible scenarios why Xiaomi’s second headphone doesn’t connect via Bluetooth, from basic checks to hidden Android/iOS settings. You’ll learn how to reset your headphones to factory settings, check synchronization between modules, update firmware, and even restore performance in case of physical damage. And if the problem lies in your smartphone, you’ll find instructions for cleaning your Bluetooth cache and resetting network settings.

We will pay special attention to the models Redmi AirDots 2/3, Mi True Wireless Earbuds 2/Pro and Xiaomi Buds 4, as their firmware and connection schemes have key differences. All solutions are tested on current versions of MIUI, Android 12-14 and iOS 15-17.

Basic checks: cover, charge and indicators

Before you dig deep into the settings, make sure the problem isn't in trivial things. Start with a visual inspection:

• 🔋 Charge level of the case: Connect the case to the power source. If the indicator does not burn or flashes red, the battery is dead. The headphones will not sync if the case does not supply power.
• 🔄 Headphone position: Headphone contacts should fit tightly to the contacts in the nests of the case. Try turning the headphones over or pressing them slightly.
• 🔴 Color of indicators: Red flashing - low charge or synchronization error. White flashing - conjugation readiness. Constant red - critical error (reset required).
• 📱 Pairing with another device: Try connecting your headphones to another smartphone or tablet. If the problem recurs, a malfunction in your headphones.

If the case is charged but the headphones don't respond to retraction, try a forced reset: put both earphones in the case, close the lid and wait 10 seconds. Then remove them and hold the control buttons on both earphones for 15 seconds (until the indicators flash twice).

⚠️ Note: On Xiaomi Buds 4 and later, the reset is done via the Mi Earphones mobile app. manual button retention may not work!

2.Chronization problems between headphones (Master-Slave)

TWS-Xiaomi headphones are master-slave, one headphone (usually on the right) connects to the phone, and the second one syncs with the first one. If the communication between them is broken, the second headphone may not be identified.

Signs of a problem:

• 🎧 Only one headphone is visible in the list of Bluetooth devices.
• 🔊 The sound comes from only one earpiece, the second is silent.
• 🔄 The indicator on the second headphone flashes red, and on the first - white.

How to restore synchronization:

1. Put both headphones in the case and close the lid for 20 seconds.
2. Remove them and hold the control buttons on both headphones for 10-15 seconds (until double blinking).
3. Connect to the headphones via the Bluetooth menu of the smartphone. If the synchronization is not restored, repeat the procedure 2-3 times.

If manual reset didn’t work, try updating your firmware through the official app. For Redmi AirDots 3 and later, updates are distributed automatically when you connect to the Internet.

3. Software glitches: smartphone, Bluetooth and cache

Sometimes the problem is not the headphones, but the settings of the smartphone, especially if the headphones worked normally before, and after updating the system or installing a new application, they stopped connecting.

What to check on your phone:

• 📱 Bluetooth Version: Outdated versions (below 4.2) may not support TWS. Update the firmware of the smartphone.
• 🗑️ Bluetooth Cash: Go to Android Settings → Annexes → Show all applications → Bluetooth and clear the cache.
• 🔄 Reset network settings: On iPhone: Settings → Mainstream → Transfer or discharge → Resetting network settings.
• 🚫 Conflict applications: Some programs (e.g. Bluetooth Auto Connect) may block the connection.

If the headphones are connected but the sound is only in one channel, check the sound settings:

• On Android: Settings → Sound → Stereo balance (should be centered).
• On iOS: Settings → Universal Access → Audiovisual → Stereo Balance.

⚠️ Note: On smartphones Xiaomi with MIUI 13+ There's a bug that can turn off Bluetooth devices when you lock your screen. To fix this, go to Settings. → Battery → Power Saving Mode and Turn Off Optimization for Bluetooth App.

Hardware malfunctions: contacts, battery, microphone

If the software methods didn't work, the problem could be physical damage, and most often, the problem is:

• 🔌 Contacts in a case: Oxidation or contamination of contact areas. wipe them with an alcohol napkin.
• 🔋 Earphone battery: If one earphone is discharged in 5-10 minutes, its battery is worn out. Check the charge level of each earphone separately in the Mi Earphones app.
• 🎤 Microphone: On noise-canceling models (e.g. Xiaomi Buds 3 Pro), a faulty microphone can block the connection.
• 📡 Bluetooth antenna: Falling or getting moisture can damage the antenna, which is why the headphone does not see the “lead” module.

How to check for hardware faults:

1. Contact test: Light a flashlight into the socket of the cover, the contacts should shine. If they are dimmed, brush them with a swallow.
2. Battery check: Put the headphones in the case for 30 minutes, then check the charge level in the application. If one headphone is 10-20% charged and the second is 100% battery problem.
3. Diagnostics of the microphone: Record the voice message from each earphone separately, and if one of them is jammed or silent, the microphone is defective.

If the headphone is physically damaged (cracks, dents, oxidation marks), do not try to disassemble it yourself - this can lead to complete failure.

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If the earphone is not charging in the case, try to bend the contacts in the socket of the case slightly upwards (neatly, without fanaticism). Often they sag over time and stop touching the areas on the earphone.

5. firmware update and reset via Mi Earphones

Many connectivity issues are solved by a firmware update. For Xiaomi headphones, this is done through the official Mi Earphones app (available for Android and iOS).

Instructions for updating:

1. Install the Mi Earphones app from Google Play or the App Store.
2. Connect the headphones to the phone via Bluetooth.
3. Open the app and select your headphone model.
4. Go to the Firmware Update section and follow the instructions.

If the update doesn’t help, do a full reset through the app:

1. In Mi Earphones, go to Settings → Resetting.
2. Confirm the action and wait for the process to be completed.
3. After reset, reconnect the headphones to the phone.

For Redmi AirDots 3 Pro and Xiaomi Buds 4 models, the app has a connection diagnostic that shows the synchronization status between the headphones and the Bluetooth signal level.

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If your headphones stop connecting after the firmware update, roll back to the previous version via the Mi Earphones app (if available).In some cases, new firmware contains bugs, especially for older models.

6. Alternative methods of connection (for power users)

If standard methods don’t work, try alternative methods that sometimes help in difficult cases.

Method 1: Forced pairing via ADB (Android)

This is a way for advanced users to manually clear the list of Bluetooth devices.

adb shell pm clear com.android.bluetooth


adb shell reboot

After completing the commands, restart the phone and try to reconnect the headphones.

Method 2: Using Developer Mode

• Activate Developer Mode on Android (7 times click on Build Number in your phone settings).
• Go to Settings → System → For developers.
• Enable Bluetooth Debugging and Bluetooth AVRCP version 1.6.
• Restart your phone and try to connect.

Method 3: Connection via PC

Some Xiaomi models (such as the Mi True Wireless Earbuds 2) can be connected to a computer via a Bluetooth adapter, and if they are detected on a PC but not on a phone, the problem is definitely with the smartphone.

⚠️ Attention: Use ADB And the developer mode can lead to unstable Bluetooth. If you're not sure what you're doing, skip this section.

7. When to contact the service center

If none of the methods worked, it’s probably a hardware problem. Contact Xiaomi Service Center for the following:

• 🔥 The earphone is warming or smells of a burn.
• 💧 Headphones fell into the water or were subjected to severe humidity.
• 🔊 One earpiece makes a constant noise or squeak.
• 🔌 Contacts in the case or on headphones are damaged (broken, oxidized).
• 📉 The battery discharges in a few minutes (blown, leakage).

The cost of repair in official Xiaomi services:

Before the service visit:

• Make sure the headphones are clean (no dirt or moisture).
• Bring a case and a charging cable.
• If the headphones are guaranteed, check its term in the Mi Home app.

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If the headphones are warranty, do not open them yourself - this will cancel the warranty service. The service center may refuse repair if they find traces of disassembly.

FAQ: Frequent questions about connecting Xiaomi headphones