Xiaomi Redmi 9C brakes: the reasons and how to fix it in 2026

Xiaomi Redmi 9C is a budget smartphone that, when released in 2020, showed excellent performance for its price category. However, over time, many users find that the device begins to “hang”, slowly open applications or suddenly reboot. If your Redmi 9C began to work worse than before, do not rush to blame “planned obsolescence” – in 90% of cases, the problem can be solved yourself.

In this article, we will analyze all possible causes of brakes, from banal memory shortages to hidden firmware errors, and give step-by-step instructions for restoring performance. We will pay special attention to the nuances that are specific to the Redmi 9C: its MediaTek Helio G35 processor, 2/3 GB of RAM and MIUI based on Android 10/11. You will learn which settings should be changed first, and which “advices” from the Internet is better to abandon, so as not to damage the system.

Important: If the brakes appeared immediately after the MIUI update, skip the introductory part and go to the section “Problems after the update.” There we collected the latest firmware bugs for the Redmi 9C and how to get around them.

1. Overloaded memory: the main enemy of budget smartphones

Redmi 9C was released with 32 or 64 GB of internal memory, of which “out of the box” is available to the user only ~22-55 GB. At the same time, the system and preinstalled applications take up to 10-12 GB, and cache and temporary files can “eat” a few more gigabytes. If there is less than 10% free space, the smartphone begins to actively slow down – this is due to the peculiarities of the F2FS file system, which Xiaomi uses in budget models.

How to check:

• 📱 Open the Settings. → The phone. → Memory.
• 🔍 Note the Other chart — if it takes up more than 5-7 GB, it’s a sign of cache clogging.
• ⚠️ If less than 3 GB is free, the smartphone is in emergency mode, when the system is forced to constantly clean the memory, which causes lags.

Decisions:

1. Manually clean the cache: 🧹 Go to Settings → Apps → App Management. 🔄 Sort by size and clear the cache from apps that are larger than 500MB (e.g. Facebook, YouTube, MIUI Gallery).
2. Transfer data to SD- card (if supported): ⚠️ Attention: Redmi 9C does not support Adoptable Storage, but you can transfer photos, videos and some applications to a microSD card up to 512 GB. Use Settings → Memory → Data Transfer.
3. Delete junk files: 🗑️ Use the built-in Cleanup utility (the broom icon in the app menu). 📂 Check Download, DCIM/.thumbnails and Android/data folders — unnecessary files often accumulate there.

Lack of RAM: How to Optimize 2-3 GB of RAM

Redmi 9C is equipped with only 2 or 3 GB of RAM. For comparison: even in 2026, the minimally comfortable Android operation requires at least 4 GB of RAM. While MIUI itself “eats” up to 1.5-2 GB, leaving user applications crumbs. If you simultaneously open Telegram, Chrome and Instagram, the system begins to forcibly close processes, which causes hanging.

How to check the use of RAM:

• 📊 Go to Settings → About Phone → Memory → RAM.
• 🔍 If 80-90% is permanently hung in the "Used" section, this is a critical level.
• 🛑 Pay attention to the apps on the Actives list – if there are games or social networks that you have closed long ago, they must be stopped manually.

Decisions:

Advanced settings (for experienced users):

• 🔧 Enable Developer → Do not remain active (reduce consumption of RAM, but will reboot applications more often).
• 🎯 Limit background processes: Developer → Process limit → Maximum 2 process.
• ⚠️ Warning: Don’t use the RAM boosters from the Play Market – they’ll only make things worse by creating extra workload.

3.Firmware problems: MIUI bugs and how to get around them

Redmi 9C officially received the last major MIUI update in 2022 (up to MIUI 12.5 on Android 11).However, even stable firmware can contain errors leading to brakes. For example, the famous bug with system overload by the process miui.analytics, which sends data to Xiaomi in the background and consumes up to 20% of the CPU.

Typical signs of firmware problems:

• 🐢 The smartphone brakes even after resetting.
• 🔄 Self-reboot 1-2 once a day.
• 📉 In Settings → The battery can be seen that the system (Android System) consumes more than 30% of the charge.

Decisions:

Critical information for Redmi 9C: after updating before MIUI 12.5.4+ The smartphone has become overheated and turned off when charging, a well-known power controller bug. MIUI 12.0.8 via Fastboot (instructions in the section "Updates and firmware»).

Background and Autoboot: Who Steals Resources?

One of the key differences between MIUI and pure Android is aggressive autoloading. Mi Video, Mi Music, and GetApps can start when you start and consume up to 300-500MB of RAM even if you don’t use them. In addition, many apps (especially Chinese ones) ignore Doze’s limitations and continue to run in the background.

How to find and disable “gluttonous” processes:

1. 🔍 Go to Settings → Battery → Battery Use.
2. 📊 Sort by Background consumption. Applications with consumption >5% in the background are candidates for shutdown.
3. ⚡ In the same menu, click on the application → Background Activity Management → select “Limit”.

List of applications that can be safely disabled:

• 🎵 Mi Music (if not used)
• 🎬 Mi Video (alternatively VLC or MX Player)
• 🛒 GetApps, Mi Pay, Mi Credit (Chinese services worthless outside of China)
• 📊 MiuiDaemon (responsible for analytics, can be disabled via ADB)

adb shell pm uninstall --user 0 name packet

The list of packages can be found in the App Inspector (app from the Play Market).-->

5.Overheating and trottling: why the smartphone "strangles" itself

The Redmi 9C is equipped with a MediaTek Helio G35 processor, which automatically reduces performance (trottling) when heated above 60°C. In low-end Xiaomi models, they often save on thermal paste, which even at normal loads (for example, watching YouTube videos), the temperature can rise to critical values.

Signs of trottling:

• 🌡️ The body is noticeably heated (especially in the upper part).
• 🐢 Suddenly “hangs” during games or video shooting.
• 📉 A sharp drop FPS in games (from 30 to 10-15).

How to check the temperature:

• 📊 Install the app AIDA64 or CPU Monitor.
• 🔍 If the processor temperature exceeds 65°C on a simple load, this is cause for concern.

Decisions:

• 🧊 Cooling: Remove the case, avoid direct sunlight, and do not use your smartphone while charging.
• ⚙️ Settings: Turn off Settings → Battery → Performance Mode (it overclocks the processor, but leads to overheating).
• 🔧 For the experienced: Reduce the maximum CPU frequency through Developer → Limit background processes.

⚠️ Warning: If the smartphone turns off when it is heated (temperature >70°C), this may indicate a battery failure or heat paste dump from the processor, in which case repairs are required at the service center.

6. Viruses and malware: a hidden threat

Xiaomi’s budget smartphones are often targeted by viruses, especially if you install apps from third-party sources (APK- files). Malware can masquerade as system processes (e.g. com.android.system) and consume resources in the background. For example, HiddenAds virus displays ads and simultaneously mines cryptocurrency, which leads to brakes.

Signs of infection:

• 📢 Appearance of pop-up ads in unexpected places (even in settings).
• 🔋 Fast battery discharge (more than 20% per hour on standby).
• 📡 Unknown Internet connections (checked in Settings → SIM-Maps and Mobile Networks → Traffic).

How to check and remove viruses:

1. 🛡️ Install Malwarebytes or Dr.Web Light (they are less system loading than Avast or Kaspersky).
2. 🔍 Complete scan (including system folders)
3. 🚫 If the virus does not get removed, reset your smartphone to factory settings (see next section).

⚠️ Warning: Some of the Play Market's "optimizers" (e.g. Clean Master, DU Speed Booster) contain malicious code themselves. Use only proven antiviruses.

7.Reset and Recovery: Last Chance

If all the previous methods didn't work, you're left with a factory reset, which is a radical but effective way to get your smartphone back to speed. On the Redmi 9C, you can do the reset in two ways:

Method 1. Through the settings menu (saves data to Mi Cloud):

1. 📱 Go to Settings. → The phone. → Resetting settings.
2. 🔄 Select Reset All Settings (not to be confused with Reset Network Settings!).
3. ⏳ Wait until it's finished (taken). 5-10 minute).

Method 2. Through Recovery (full reset, removes everything):

1. 🔌 Turn off your smartphone.
2. 🔘 Press Power + Volume up until the Mi logo appears.
3. 📛 From the Recovery menu, select Wipe Data → Wipe All Data.

What to do after the discharge:

• 🔄 Do not restore data from backup – this can bring back old errors.
• 📥 Install applications selectively (one at a time) by checking performance.
• 🔧 Turn off automatic app updates in the Play Market.

💡

Factory reset deletes all data, including photos and messages. Pre-save important information to Mi Cloud or PC!

8. Hardware malfunctions: when it's time to go to service

If the smartphone brakes even after resetting and all software methods have been tried, the problem may lie in the "hardware" of Redmi's typical hardware faults. 9C:

How to check for "iron":

• 🔧 Use the CPU Throttling Test (checks processor trottling).
• 📊 Run AIDA64 → Tests → Memory (if read/write speed is below 100MB/s, eMMC issues).
• 🔋 Check battery wear in AccuBattery (if health <80% - replacement is required).

⚠️ Warning: If your smartphone starts to brake after falling or getting moisture, don't turn it on, it could lead to a short circuit.

FAQ: Frequent questions about Redmi 9C brakes