Why Xiaomi Airdots 2 is not connected to the headphone full guide on diagnostics and repair

Did you get the Xiaomi Mi True Wireless Earphones 2 (Airdots 2) out of your case, but one headphone stubbornly refuses to connect? TWS-In 80 percent of cases, the malfunction is due to software failures or improper synchronization, but sometimes hardware failures are to blame. In this article, we will examine all possible reasons why one Airdots 2 earphone does not work, from a trivial battery discharge to damage to contacts in the case.

It's important to understand that Xiaomi Airdots 2 (TWSEJ04LS) is based on the Realtek RTL8763B chip, which is responsible for wireless communication and synchronization between headphones. If one of them falls off, the problem can be both in the firmware and in the physical damage of the antenna. We will not offer "magic" solutions like "reboot the phone" - instead, you will get detailed diagnostics with step-by-step instructions, compatibility tables and even hidden case functions that are not written in the official documentation.

Before you take your headphones to the service center, check out that your case may be one of the 7 main reasons we analyze below. And if you’ve already tried Google the solution but come across tips like “wipe your contacts with alcohol” (which often only makes the problem worse), here you’ll find exclusive methods for resetting a pair of headphones through the engineering menu and tests to check for hardware malfunctions.

1. Battery discharge or battery failure

The most obvious, but often overlooked, reason is that one of the headphones is undercharged. Airdots 2 uses a 40mAh lithium polymer battery in each headphone, and if one of them is down to 0%, it not only won't play the sound, it can also block the pair from connecting to the phone.

How to check:

• 🔋 Place both earbuds in a case for 10-15 minutes (even if the indicator is green.
• 📱 Open the Mi Home or Xiaomi Wear app (if the headphones are tied to your account). → Headphones should display the charge level of each headphone separately.
• 🔌 Connect the case to charging and look at the indicators: if one headphone flashes red and the second flashes white, this is a signal of a different level of charge.

If after full charging the problem remains:

• ⚡ Check the contacts in the case: often oxidation or contamination leads to a bad charge. wipe them with a dry cotton swab (do not use alcohol - it can damage the coating!).
• 🔄 Try forced resetting of headphones (instructions in the next section).

⚠️ Warning: If the headphone is discharged in a few hours in standby mode, this is a sign of battery degradation, in this case, only replacing the battery (cost) will help. ~500-800 rubles in the service).

2. failure of synchronization between headphones

Xiaomi Airdots 2 uses Bluetooth 5.0 with A2DP and AAC support to synchronize sound. If one earphone doesn't connect, there's likely a pairing failure between the left and right devices.

• 📵 Abrupt Bluetooth shutdown on your phone.
• 🔄 Updates to the firmware of headphones or smartphone.
• 📦 Long-term storage without use (more than 2 weeks).

How to restore synchronization:

Make sure both headphones are in the case | Hold the button on the case for 15 seconds (the indicator flashes red and white) | Remove the headphones - they must automatically sync | Connect to them via Bluetooth as a new device-->

If the dumping didn't help:

1. Open Bluetooth settings on your phone.
2. Find Airdots 2 in the list and click Forget the device.
3. Return the headphones to the case, close the lid for 10 seconds, then remove.
4. Press and hold the touchpad on the right earpiece for 10 seconds until the indicator starts flashing white.
5. Repeat the same for the left earpiece.
6. Connect to the headphones via Bluetooth – they should be defined as Mi True Wireless Earphones 2.

⚠️ Note: If after reset, the headphones are defined as two separate devices (Mi True). Wireless_Left and Mi True. Wireless_Right), This means that the firmware is damaged, in which case you will need to flash it over the PC (instructions in the section). 5).

3. Bluetooth problems on your phone or device conflict

Sometimes the problem is not with the headphones, but with the smartphone, especially with Android 10+ devices, which implements the Fast Pair feature, which can conflict with Airdots 2.

Signs of a problem on the phone side:

• 📱 The headphones are connected, but the sound is only in one channel.
• 🔄 Bluetooth is constantly switched off and turned back on.
• 🚫 Airdots 2 is displayed as "Unconnected" in the list of devices".

Decisions:

1. Turn off Fast Pair: Go to Settings → Google → Devices and Exchange → Fast Pair. Turn off the option to Show Notifications when Devices are Deviced.
2. Reset Bluetooth settings: Settings → System → Settings Reset → Reset Wi-Fi, mobile network and Bluetooth Attention: after that you will have to reconnect all Bluetooth devices.
3. Check compatibility: Some phones (such as Samsung on One UI) have issues with Airdots 2 due to codec conflict. Try connecting to another device (such as a laptop or tablet).

💡

If the headphones don't connect to your iPhone, try connecting them to your Android device first, and then resetting.This helps wake up the Bluetooth chip in Airdots 2.

Physical damage: contacts, speaker, antenna

If the software methods didn't work, it's worth checking the hardware, and Airdots 2 is the most vulnerable:

• 🔌 Charging contacts (oxidation or pollution).
• 🎧 Dynamics (membrane damage or wire break).
• 📡 Bluetooth antenna (breakdown after fall).

How to diagnose:

1. Contacts: Light the metal contacts in the case and on the headphones. If they are dimmed or covered with plaque, brush them with a brush (not sandpaper!). Check if the contacts in the case are bent - this is a common problem after falls.
2. Speaker: Hold the earphone to your ear and turn the music on at maximum volume. If you hear wheezing or crackling, the speaker is damaged. Blow the speaker down the hole -- if the sound is not restored, the membrane is torn.

Antenna:

• If the earphone is not determined by the case (does not flash when extracted), the antenna is likely to be severed.
• Try to bring the headphone to the phone at a distance of 1-2 cm If the connection appeared, the problem is in the antenna.

To update the firmware:

• 📱 Install Mi Earphones (not to be confused with Mi Home!) from APKCombo (it is removed from Google Play).
• 🔄 Connect your headphones to your phone and open the app. If you have an update, you'll see an Update button.
• ⚠️ Don't interrupt the process! The update takes ~5 minutes, the case should be charged at 50%+.

Hidden Case Teams:

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If your headphones stop working after you update your firmware, reset them through the engineering menu and reconnect them, which solves the problem 90 percent of the time.

6 Conflict with other Bluetooth devices

Xiaomi Airdots 2 uses Bluetooth Low Energy (BLE) to save power, but this can cause conflicts with other devices, especially if they operate at the same 2.4 GHz frequency (e.g. Wi-Fi routers, wireless mice, smart light bulbs).

Signs of conflict:

• 🔄 The headphones are connected, but the sound is interrupted.
• 📵 One earphone is turned off in 1-2 minutes.
• 🚫 In the Bluetooth list, the device appears then disappears.