Xiaomi Redmi 9 freezes: a complete analysis of the reasons and solutions

Xiaomi Redmi 9 is one of the most popular budget smartphones, but even it is not immune from sudden freezes. The screen stops responding to touches, applications freeze for several seconds, and sometimes the phone even requires a forced reboot. If your device begins to work slower or regularly “thinks”, do not rush to blame the manufacturer: in 80% of cases the problem can be solved on your own without contacting a service center.

In this article we will analyze all possible causes of freezes - from a banal lack of memory to hardware faults. You'll learn how to diagnose a problem based on its symptoms, which settings to optimize first, and when it's really time to take your phone in for repair. We will pay special attention unique “diseases” Redmi 9related to its hardware and firmware MIUI.

⚠️ Attention: If freezes are accompanied by reboots yourself, blue screen or appearance of artifacts on the display —this may indicate a critical malfunction of the motherboard. In this case any manipulations with the software are useless, and the phone requires professional diagnostics.

First, answer one question - this will help narrow down the range of possible reasons:

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1. RAM overload: why Redmi 9 “slows down” after several hours of operation

Redmi 9 equipped with 3–4 GB of RAM (depending on the modification), but even this may not be enough if dozens of background processes are running simultaneously. Main symptom: the phone starts to “lag” after prolonged use, and in the task manager there are 20+ running ones applications.

The fact is that MIUI aggressively caches data to speed up the restart of apps. But over time, this cache grows, and the system does not have time to clear it. As a result less than 500 MB of free memory remains, and the smartphone begins to “freeze” when switching between tasks.

How to check:

1. Open Settings → About phone → Memory.
2. Look at the RAM usage graph.
3. If less is free 1 GB the problem is overload.

Solutions:

• 🔄 Clearing the cache manually: Go in Settings → Applications → All applications, select the most “gluttonous” one (for example, Facebook or TikTok) and click “Clear cache”.
• ⚡ Disabling autorun: In the same application settings, find the "Autorun" item and deactivate it for unnecessary apps.
• 📱 Using “Light” versions: Replace heavy social networks (for example, Instagram) with their lighter versions (Instagram Lite).
• 🔧 MIUI settings: Activate the “Performance” mode in Settings → Special features → Performance mode.

⚠️ Attention: Do not use “memory boosters” from Google Play —they will only worsen the situation, creating additional load. MIUI already has a built-in optimizer that works more efficiently than third-party utilities.

2. Overheating: why the Redmi 9 “freezes” during games or charging

Redmi 9 is built on a processor MediaTek Helio G80that is prone to overheating under high loads. If the phone starts slow down after 15-20 minutes of play or while charging, the reason is most likely thermal throttling — automatic performance reduction to protect against overheating.

How to check the temperature:

1. Install the application AIDA64 or CPU Monitor.
2. Start a game or load (for example, video rendering).
3. If the processor temperature exceeds 65°C, and the battery exceeds 45°C, this is critical overheating.

Causes of overheating Redmi 9:

• 🔥 Charging + gaming: Simultaneous high load on the processor and battery doubles the heat dissipation.
• ☀️ Direct sunlight: Even 5 minutes in the sun can heat the case up to 50°C.
• 🚫 Clogged radiator: Dust in the charging connector or under the back cover impairs heat dissipation.
• 🔋 Faulty battery: A swollen battery heats up on its own and heats up other components.

Solutions:

1. Game mode: Turn it on Settings → Special. features → Gaming mode and activate the “FPS Limit” option. This will reduce the load on the processor.
2. Cooling: Remove the case during games and use the stand for better ventilation.
3. Charging: Do not play while charging - connect the phone to the network only in standby mode.
4. Cleaning: Blow out the charging connector with compressed air (without alcohol!).

⚠️ Attention: If the phone turns off when heated to 50–55°C, this is a sign of a faulty temperature sensor or battery. Replacing the battery on Redmi 9 yourself without experience can damage the display cable - in 30% of cases this leads to the appearance of dead pixels.

What to do if Redmi 9 overheats and turns off?

Do not turn it on right away - let it cool for 15-20 minutes. If after turning on a temperature warning appears, reset the settings to factory settings (see section 5).

3. Problems with the firmware: MIUI bugs and unsuccessful updates

MIUI is one of the most customizable shells Android, but its frequent updates do not always go smoothly. If Redmi 9 starts to freeze after updatethe software is most likely to blame. Typical symptoms:

• Freezes on the logo MI when turned on.
• Spontaneous reboots 1-2 times a day.
• Lags when opening standard applications (Camera, Gallery).

The most problematic versions MIUI For Redmi 9 (according to the forums w3bsit3-dns.com and Xiaomi Community):

MIUI version	Release date	Typical bugs	Solution
MIUI 12.0.8	October 2021	Freezes when connecting Bluetooth	Rollback to 12.0.7 or update to 12.0.9
MIUI 12.5.2	March 2022	Lags in the interface, slow animation	Cache clearing via Recovery
MIUI 13.0.1	January 2023	Spontaneous reboots when the battery is low	Reset to factory settings

How to fix:

1. Update rollback: If the problem appeared after the update, try to roll back via Settings → About phone → System update → Three dots → Select update package (you need the old file firmware).
2. Clear cache: Hold Power + Volume upin the menu Recovery select Wipe Cache.
3. Manual firmware: Download the stable version MIUI from the official website Xiaomi and flash via Fastboot (instructions below).

⚠️ Attention: Firmware via Fastboot erases all data first! Make a backup via Settings → Advanced → Backup.

4. Viruses and malware: hidden miners and advertising bots

Budget smartphones like Redmi 9 are often targets for viruses, especially if you install applications from third-party sources. Signs of infection:

• The phone is heating up and discharges by 20–30% per hour in standby mode.
• Appears unfamiliar advertising in the status bar or on top of other applications.
• In Settings → Battery an unknown application is visible, consuming 10%+ of the charge.

Where to catch a virus on Redmi 9:

• 📱 Pirated APK: Hacked games or apps from telegram channels.
• 🌐 Fake sites: "Free" movies or music with an offer to download the player.
• 📎 Attachments in messengers: Files with the extension .apk from unknown senders.

How to remove a virus:

1. Safe Mode: Hold down the power button, hold down “Turn off”, select “Safe Mode”. Only system applications work in it - if the lags disappear, third-party software is to blame.
2. Search for suspicious apps: Go to Settings → Applications and sort by installation date. Remove everything unfamiliar.
3. Antivirus: Install Malwarebytes or Dr.Web Light and scan the system.
4. Factory reset: If a virus is embedded in system files, only a full reset will help (see section 5).

⚠️ Attention: Some viruses disguise themselves as system applications (for example, Google Play Services). Before deleting, check the name in Google —real system apps cannot be deleted.

5. Resetting to factory settings: when will it really help

If all the previous methods did not work, the last chance to bring Redmi 9 to life is hard reset. This will delete all data, but clear the system of garbage, viruses and lost settings. When this is justified:

• The phone freezes on the logo MI and does not boot further.
• The lags appeared after an unsuccessful update.
• The virus is embedded in system files and cannot be removed by the antivirus.

How to reset:

1. Through settings: Settings → About the phone → Reset settings → Erase all data.
2. Via Recovery:
   1. Turn off the phone.
   2. Hold Power + Volume up for 10 seconds.
   3. Select from the menu Wipe Data → Wipe All Data.
   4. Confirm the action and wait for the reboot.

What to do after the reset:

• 🔄 Do not restore the backup! If the problem was a virus or broken settings, it will return with backup copy.
• 📱 Install applications one by one and monitor the phone’s reaction.
• ⚡ Disable auto-update of applications in Google Play.

⚠️ Attention: If after resetting the phone the hardware still does not turn on or freezes on the screensaver, the problem is in Hardware (memory, processor, motherboard). In this case, diagnostics are required at a service center.

How to save data before resetting if the phone does not respond to touches?

Connect Redmi 9 to the PC via USB, enable USB debugging (if the phone responds at least somehow) and use the app Xiaomi ADB/Fastboot Tools to extract files.

6. Hardware faults: when it’s time to get it repaired

If none of the software methods helped, the problem lies in the hardware. Redmi 9 has several typical hardware weaknesses:

1. Wear of flash memory (eMMC)

Budget smartphones use cheap memory eMMC, which wears out after 2-3 years of active use. Symptoms:

• The phone freezes when recording video or installation of applications.
• Files are damaged (photos are opened with artifacts, videos are “torn”).
• In AIDA64 shows poor condition memory (item "Storage").

Solution: Replacement of the memory chip (cost - 30–50% of the phone price).

2. Battery malfunction

Over time, lithium-polymer batteries degrade, and the controller begins to malfunction. Symptoms:

• The phone turns off at 20-30% charge.
• Charging is jerky (sometimes fast, sometimes slowly).
• The case is swollen in the battery area.

Solution: Replacement of the battery (the original costs ~1500–2000 ₽).

3. Problems with the motherboard

The most common problems are:

• 🔌 Power controller —the phone does not turn on or turns off when charging is connected.
• 📡 Wi-Fi/Bluetooth module —lags when connecting to the network.
• 🎮 Graphics chip —artifacts in games or “torn” animations.

Solution: Diagnostics in the service (board repair costs 50–70% of the cost of the phone).

⚠️ Attention: If after a fall or impact the phone starts spontaneously reboot, check the integrity of display cable i battery contacts. In 40% of cases, the problem is solved by reconnecting the cable (free in the service).

7. MIUI optimization: hidden settings to speed up Redmi 9

Even if yours doesn't freeze critically, a few tweaks will help make it work smoother. These settings do not require root access and are safe for the system. Redmi 9 does not freeze critically, a few tweaks will help make it work smoother. These settings do not require root access and are safe for the system.

1. Disabling animations

Reducing or disabling animations speeds up switching between applications.

1. Activate Settings → About phone → MIUI version (press 7 times to enable developer mode).
2. Go back to Settings → Advanced → For developers.
3. Find items:
   • Window animation scale → Disable
   • Transition animation scale → Disable
   • Animator duration → Disable

2. Limiting background processes

By default MIUI allows up to 20 processes to run in the background. You can reduce this number:

1. Go to Settings → For Developers.
2. Find Background process limit.
3. Select Maximum 2-3 processes (this will not kill instant messengers, but will limit unnecessary applications).

3. Disabling MIUI Optimization

This feature sometimes conflicts with applications and causes lags. To deactivate it:

adb shell pm disable-user --user 0 com.miui.personalassistant

(Requires connection to a PC and enabled USB debugging.)

4. Using “Light” themes

Dark themes and wallpapers with a minimalist design reduce the load on the processor. Install the theme Dark Mode or Minimalist in Settings → Display → Themes.

⚠️ Attention: Not all settings from developer mode are safe. Do not change settings related to RAM, CPU or GPUif you do not understand their purpose - this may lead to irreversible damage to the system.

FAQ: Frequently asked questions about Redmi 9 freezing

My Redmi 9 only freezes when connected to Wi-Fi. What's the matter?

Most likely, the problem is router or network settings. Try:

1. Reboot the router.
2. Forget the network on your phone and connect again.
3. Change the Wi-Fi channel in the router settings (from Auto to 6 or 11).
4. Disable IPv6 in the Wi-Fi settings on your phone.

If lags remain, check your phone for viruses - some of them are activated when connected to the network.

After the fall, the phone began to slow down. Is this a software or hardware problem?

Most likely, hardwareThe most often affected by impacts are:

• Display cable (symptoms: artifacts, non-functioning touchscreen).
• Battery (symptoms: spontaneous shutdowns, slow charging).
• eMMC memory (symptoms: lags when writing files, damaged photos).

Take the phone to a service for diagnostics - self-repair may aggravate the problem.

Is it possible to speed up Redmi 9 using custom firmware?

Yes, but with reservations:

• ✅ Pros: Firmwares like LineageOS or Pixel Experience are deprived of a “heavy” shell MIUI and work faster.
• ❌ Cons:
  • Loss of warranty (if it is still valid).
  • Risk of the phone being “bricked” if there is a firmware error.
  • Some functions (for example, IR blaster) may not work.

If you decide, use only the firmware for the model Redmi 9 (lancelot) and follow the instructions from the forum XDA Developers.

Why does Redmi 9 slow down when shooting video in 1080p?

It uses a budget processor Redmi 9 uses a budget processor Helio G80which is not optimized for recording video in high resolution. 1080p@60fps lags may occur due to:

• Lack of performance video processor.
• Slow recording to eMMC memory.
• Overheating (camera and processor are located close together).

Solutions:

1. Shoot in 1080p@30fps or 720p@60fps.
2. Close all background applications before shooting.
3. Use third-party cameras (for example Open Camera) with a lower bitrate.

How to check if the memory in Redmi 9 is dying?

Use the application AIDA64:

1. Open a tab Storage.
2. Look at the parameter Health status (Health).
3. If the value is lower 90%, the memory is worn out and requires replacement.

Also pay attention to:

• Slow writing/reading of files.
• Errors when copying data to a PC.
• Spontaneous disappearance of files.