Why the alarm clock does not work on Xiaomi Android smartphones: a full analysis of the causes and solutions

You set an alarm on the Xiaomi Redmi Note 12 or POCO X5 Pro, but you overslept in the morning because it didn't work? This problem is familiar to many owners of smartphones on MIUI, Xiaomi's branded shell. Unlike "naked" Android, here alarms are controlled not only by the standard Watch app, but also by system services that can conflict with energy saving, background restrictions or even hardware features of the processor.

In this article, we’ll look at all the possible reasons why Xiaomi’s alarm clock might not work, from commonplace user errors to hidden firmware bugs, how to check battery optimization settings, why alarm clocks don’t work in “Do Not Disturb” mode with exceptions included, and what to do if a problem occurs after the MIUI 14/15 update, and at the end, a quick diagnostic checklist and answers to frequent questions.

1. Checking the basic alarm clock settings

Before you dig deeper, make sure that the problem is not an elementary error. Go to the Watch app (the icon with the dial) and check:

• ⏰ Time of alarm clock – you may have accidentally set it for the evening instead of the morning (check the format) 12/24 hourly).
• 🔔 Signal sound – if you select “No Sound” or a melody that is too quiet, the alarm will go off, but you won’t hear it.
• 🔄 Repeatability – a single alarm clock will not work daily.
• 📴 Vibration - on some models (Redmi 10, POCO M4 Pro) the vibration is switched off separately from the sound.

Also, look at the alarm labels on the home screen. If you delete the widget or the Watch app icon, it doesn't affect the alarm clock, but it can be confusing. The alarm clocks themselves are stored in the system regardless of the labels.

Conflict with the energy saving regime

The most common reason for silent alarms on Xiaomi is aggressive battery optimization. The MIUI default restricts background activity of applications, including the Watch, to extend battery life, and as a result, the alarm may fail if:

• 🔋 The phone was in ultra-long wait mode (on automatically at low charge).
• ⚡ The option to limit background activity for the Watch application is enabled.
• 🛑 App Watch added to the list of Deep Optimization.

To fix this:

1. Go to Settings → Applications → Application Management → Watches → Battery Optimization.
2. Select No Limits (if there is no such item, turn on Allow Background Activity).
3. In the same menu, check that the app has AutoRun permission.

Open Settings → Applications → Hours

Select “No Limits” in Battery Optimization

Enable AutoRun for the Watch application

Reboot your phone after the changes-->

Some firmware (MIUI 13 and older) may need to further disable Adaptive Battery Optimization in Settings → Battery → Battery settings. This will reduce battery life a little, but ensures that alarm clocks are running smoothly.

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If after turning off the optimization alarm clock worked, but the battery began to go down faster, try an alternative solution: set a third-party alarm app (for example, Sleep as Android) and add it to the exceptions optimization.

3.The Impact of the Do Not Disturb (DND) Regime

Xiaomi's Do Not Disturb (DND) mode blocks all notifications, including alarm clocks, unless exceptions are set up. Many users forget that:

• 🚫 By default, alarm clocks are not included in the list of permitted notifications in the DND.
• 🔕 If you manually added an alarm to the exceptions, but it still does not work, check the schedule. DND — It is possible that the mode is activated automatically at night.
• 📱 On some models (Xiaomi 13, Redmi) K50) There is a separate alarm switch in the settings DND.

How to set up:

1. Go to Settings → Sound and vibration → Do not disturb.
2. Select Allow exceptions → Alarm clocks and turn on the option.
3. If you use a schedule, make sure it doesn’t overlap with the alarm clock time.

4 Problems after MIUI Update

MIUI updates often bring new bugs, especially in the first builds. If the alarm clock stopped working after an update (for example, from MIUI 13 to 14), the reasons may be as follows:

If the problem occurs after the update, try:

1. Clear the cache and data of the Watch app (in Settings → Apps). Attention: this will remove all stored alarm clocks!
2. Reverse to the previous version of MIUI (if backup is available).
3. Set an alternative alarm from Google Play (e.g. Timely or Alarmy).

⚠️ Attention: On beta versions MIUI (especially for Xiaomi 13T or POCO F5) The alarm clocks may not work due to test limitations. → The phone. → Version. MIUI — If you have a “Beta” mark, consider switching to a stable branch.

5. Hardware causes: battery and processor

If the software methods did not help, the problem may lie in the iron:

• 🔋 Weak battery: if the phone shuts down at night due to a discharge, the alarm won't work.Check the battery health in Settings → Battery → Battery condition (normal - from 80% capacity).
• ⚡ Deep discharge: if the phone is discharged “to zero”, the internal clock is confused, and the alarm clocks may not work correctly.
• 🛠️ Problems with the motherboard: on old models (Redmi) 4X, Mi A1) The quartz resonator responsible for time may be damaged.

How to diagnose:

1. Connect your phone to overnight charging and check if the alarm goes off. If so, the battery is a problem.
2. Compare the time on your phone to a reference (e.g. time.is). If the discrepancy is more than 1 minute, reset your network settings (Settings) → SIM-maps and mobile networks → Resetting network settings).
3. Check your phone for overheating: If the processor overheats at night (for example, due to background tasks), the system may be forced to shut down.

On removable battery models (Redmi 3S, Mi Max), try to remove the battery for 10 seconds, which will reset the time cache. On non-removable batteries, a similar effect is given by hard reset (press Power + Volume up for 15 seconds).

6. Conflict with third-party applications

Some apps can block alarm clocks even if you don’t notice it:

• 🛡️ Antiviruses (e.g. Avast, 360 Security) – may consider alarms suspicious activity.
• 🔒 Task Managers (e.g. Greenify) – Forced to close background processes.
• 🎵 Music players (for example, Spotify, Yandex Music) - can capture the audio stream, because of which the alarm clock plays without sound.

How to find the culprit:

1. Launch your phone in Safe Mode (press the power button → Safe Mode). If the alarm goes off, the problem is in a third-party app.
2. Turning to delete recently installed programs, checking the alarm clock.
3. Check the permissions for applications in Settings → Apps → Resolutions – some can block sound or vibration.

⚠️ Attention: On Xiaomi with MIUI 14+ There's a hidden feature called Notification Optimization that can block alarms from third-party apps. To turn it off, type ##2664## in the Phone app and select Disable Notification Optimization.

7. Alternative solutions: if nothing helps

If the standard methods don’t work, try:

• 🔄 Resetting: Return the clock and sound settings to factory settings (Settings) → System system → Resetting settings → Reset application settings).
• 📱 Third-party alarms: Install Sleep as Android or Alarmy – they bypass restrictions MIUI through their own mechanisms of awakening.
• ⚙️ ADB-For advanced users, disable optimization via computer: adb shell dumpsys deviceidle whitelist +com.android.deskclock (Developer Mode and Debugging Required) USB).

On NFC models (Xiaomi 13 Pro, POCO F4 GT), you can use smart bracelets (such as the Mi Band 7) to duplicate alarm clocks. Set up sync in the Mi Fitness app - even if the phone is asleep, the bracelet vibrates.

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If the alarm clock doesn’t work only at a certain time (e.g., 3 to 5 a.m.), the problem may be with the Linux task scheduler used in MIUI. The solution is to set the alarm 1 to 2 minutes earlier or later than the problem time.

FAQ: Frequent questions about alarm clocks on Xiaomi