You picked up the Xiaomi Redmi 9C to check the notifications, and suddenly the screen goes out, the MI logo pops up, and then the phone turns on again a few seconds later, and it repeats itself, turning the smartphone into a brick with an endless load cycle. Sounds familiar? This problem is common to many owners of the Redmi 9C budget model (codenamed angelica), and its causes can be rooted in software failures and hardware malfunctions.
Unlike flagship devices, where symptoms are often associated with CPU overheating or firmware conflicts, Redmi 9C usually blames triggers: an unstable MIUI core, a worn-out battery or damaged system files. In this article, we will analyze all possible scenarios, from basic actions that you can perform yourself, to signs that indicate a need for repair. Importantly, some methods require disassembling the phone, so evaluate your skills soberly!
1.Diagnostics problem: why the Redmi 9C goes into rebut
Before you rush to fix the problem, determine its nature.Spontaneous reboots Xiaomi Redmi 9C are divided into three types:
- 🔄 Cyclical reboot: The phone turns on, loads to the logo or desktop, then turns off again.
- ⚡ Random reboots – the device restarts 1-2 times a day for no apparent reason (e.g. while calling or playing a game).
- 🔥 Reboot from overheating - the screen goes out at high load (start camera, games, charging), the body is hot.
Each type indicates different reasons:
| Type of reboot | Probable cause | Can I correct myself? |
|---|---|---|
| Cyclical | Bootloader damaged, firmware failure, short circuit on board | Partially (reset, flashing) |
| Random reboots | Application conflict, battery wear, MIUI errors | Yes. |
| Overheating. | Thermopaste dried, dust-clogged cooling system, faulty battery | No (disassembly required) |
🔍 How to determine exactly the cause? Enable Developer Mode (click 7 times on Version) MIUI In Settings → About Phone) and activate Error Log in Settings → Additionally. → After the next reboot, check the logs in the Error Report app (look for lines with kernel panic or watchdog reset).
2. Software solutions: from simple to complex
In 70% of cases, the software is to blame. Start with the safest methods:
Forced reset
If your phone is stuck in a loop, try the hard reset:
- Press the Power + Volume button up for 10-15 seconds.
- Wait for the vibration and release the buttons.
- If the Fastboot menu appears, select Reboot with the volume button and confirm with Power.
💡
If you have a hard reboot, and the problem is repeated, you go straight to reset, and that's a sign of a deep system failure.
Reset to factory settings
Reset deletes all the data, but often solves the problem.
- 📱 Through the menu: Settings → The phone. → Resetting settings → Erase all data.
- 🔧 Using Recovery: Turn off the phone. Click the power. + Volume up before the Mi logo appears. Select Wipe Data → Wipe All Data (control – volume buttons, confirmation – power).
⚠️ Warning: If the phone goes back into the reboot cycle after it's reset, it's the firmware or the hardware problem.
2.3 Fastboot flashing
It is critical for Redmi 9C to use firmware with MIUI version no lower than 12.0.3 - earlier builds contain a bug with a watchdog timer that causes random reboots. Download the official firmware for angelica from en.miui.com and infollowing these steps:
Download the Mi Flash Tool|Unpack the firmware in a folder without Cyrillic|Install Qualcomm drivers|Charge your phone at least 50 times%|Connect the original USB-cable
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1. Turn off the phone.
2. Press <Power> + <Loudness down> to log into the Fastboot.
3. Connect the phone to the PC.
4. In the Mi Flash Tool, select the firmware folder and click "Refresh".
5. Press "Flash" (select "clean all" option).
6. wait until the completion (green tick).⚠️ If the process is 99% frozen or there is an anti-rollback error, you are trying to install an older version. MIUI, This requires unlocking the bootloader (see section 4).
3. Battery problems: how to check and what to do
The 5,000mAh battery in the Redmi 9C is one of the weak spots of the model, and after 1.5 to 2 years of use, it loses up to 30 percent of its capacity, and the charge controller starts to crash, causing reboots, and signs of a battery problem:
- 🔋 The phone is rebooted when connecting / disabling charging.
- 📉 The percentage of charge jumps (for example, from 50% drops to 15%).
- 🔥 The body is very heated in the battery area.
🔧 Decisions:
- 🔌 Try another charger (original on the device) 10W or 18W).
- 🔄 Calibrate the battery: completely discharge the phone, then charge to 100% without interruptions.
- 🔧 If the battery is less than 70% healthy, replace the battery (cost) ~1500–2000 ₽ service-centre).