The Xiaomi Mi 9, released in 2019, is still a popular smartphone due to its powerful hardware and affordable price. But even reliable technology sometimes fails: the phone stops responding to the on button, the screen stays black, and charging does not help. If your Mi 9 suddenly “died” – do not panic. In 80% of cases, you can solve the problem yourself without resorting to expensive repairs.
In this article, we'll look at all the possible causes, from a simple battery discharge to serious hardware malfunctions, how to tell a software failure from a motherboard failure, what manipulations are safe to do at home, and when to contact a service center, and we've collected step-by-step instructions with photos and videos, current proven recovery methods, and answers to frequent questions from owners.
Important: if the phone is responding to charging (lights on, vibrates) but doesn't turn on, that's one scenario. If the Mi 9 is completely dead (no buttons, no charging, no PC connection) - another. We'll look at both.
1.Discharged battery or charging problems
The most common reason is a deep battery drain. Xiaomi Mi 9 is equipped with a 3300 mAh lithium polymer battery, which eventually loses capacity. If the phone has been empty for several days (or months), the power controller can block charging.
How to check:
- 🔌 Connect the original charger (minimum) 18W) cable USB Type-C. Try another charger - sometimes the problem is in the power supply.
- ⏳ Leave your phone charging for at least 30 to 60 minutes. Even if the indicator doesn't burn, the battery can gradually wake up».
- 🔄 Try charging from another device (like Power Bank) or connect to a new device. USB-port.
- 🔍 Light a flashlight on the screen at an angle - sometimes the image is, but the backlight does not work.
If there is no reaction after an hour of charging, try the forced start:
- Get the charger on.
- Press the Power + Volume button for 15-20 seconds.
- Let go of the buttons. If the phone vibrates or the Mi logo appears, the battery starts charging.
⚠️ Note: Do not use "left" chargers with voltage higher 5V/3A. This could damage the Mi power controller. 9.
2. Software failures: freeze, bootloop, "brick"
If the phone vibrates when you press the buttons, but does not load beyond the Mi logo or is stuck in a bootloop cycle, there is a problem with the software.
- 📱 Failed update MIUI (particularly OTA low-powered).
- 🔄 Interrupted firmware via Fastboot or Recovery.
- 🛠️ Installation of custom ROM or inappropriate TWRP.
- 🦠 Virus software that damages system files.
How to restore:
Method 1: Hard Reset (Hard Reset)
Resets to factory settings, but saves data in memory (if the partition) /data intact).
Turn off the phone (clip the power supply) + Volume increase by 10 seconds)|Keep your food on. + Increase the volume before the appearance of the Mi logo|In the Recovery menu, select Wipe Data → Wipe All Data|Confirm reset and reboot-->
If the phone boots after reset, but requires a password from the Mi Account, see the section on unlocking below.
Method 2: Fastboot Firmware
You will need a computer with installed drivers ADB/Fastboot and the official firmware for Mi 9 (codename).
Step-by-step:
- Download the firmware from en.miui.com (select the Stable version for your region).
- Unpack the archive in the platform-tools folder (where fastboot is installed).
- Press the power on the phone + Reduce volume, connect to the PC.
- In the command line, run: fastboot flash all name file firmware.zip
- Wait for the end (10-15 minutes) and restart the phone with the command: fastboot reboot
⚠️ Note: Fastboot firmware erases all data, including photos and apps. If your phone has Mi Cloud enabled, restore backup after startup.
What to do if the firmware is interrupted?
Hardware malfunctions: from battery to motherboard
If the phone doesn’t respond at all (no vibration, charging indication, sounds), there is a possibility of hardware failure.
| Symptoms. | Probable cause | Method of inspection/repair |
|---|---|---|
| The phone does not charge, but turns on from charging another device | Faulty Type-C connector or charging controller | Check the jack for physical damage. Replace the port or the power charge. |
| The phone heats up when charging, but does not turn on | Short circuit in the battery or power chain | Measure the voltage on the battery with a multimeter (should be 3.7–4.2V). Replace the battery. |
| Vibration is there, but the screen is black. | The display plume or the matrix itself is damaged. | Connect your phone to an external monitor USB-C → HDMI. If there is an image, there is a problem in the screen. |
| The phone does not respond to buttons, no indication | Maternal board malfunction (often after falling or getting moisture) | Diagnostics in the service: checking the power chains, replacing chips (for example, PMIC) |
Xiaomi Mi 9 has a common problem with the chip UFS 2.1 (memory) If it fails, the phone will not turn on, but can be determined by the computer as an unknown device, in which case it requires soldering of the chip - repair will cost 3-5 thousand rubles.
How to diagnose hardware breakdown yourself:
- 🔦 Light a flashlight on the screen – if there is a weak image, the problem is in the backlight.
- 🔊 Connect headphones – if you press the buttons you hear sounds (for example, cameras), the display or plume is faulty.
- 🌡️ Check the temperature of the case: if the phone is very hot when turned off, it is possible to short on the board.
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If the phone falls or gets wet, don't turn it on right away! Let it dry for 24 to 48 hours in rice or silica gel. Trying to turn on with moisture inside can cause contacts to corrosion.
4. Problems with the power button or flexible plume
The power button on the Mi 9 will wear out or stick over time, and the flexible plume connecting the button to the motherboard may also be damaged.
- The button fails or does not press.
- The phone is only activated after multiple clicks.
- The vibration is working, but the screen is not lighting up.
How to check:
- Remove the back cover (need a mediator and a hair dryer to soften the glue).
- Disconnect the battery and check the contacts of the power button on the plume.
- Connect the battery back and try to start the phone by closing the button contacts with tweezers (careful!).
If the phone turns on when the contacts are closed, the problem is the button or the plume.
- Power button: ~800-1500 rubles.
- Flexible plume: ~1000–2000 rubles (depending on the service).
⚠️ Warning: When disassembling the Mi 9, it is easy to damage the fingerprint scanner plume (it goes under the battery.
5. Blocked bootloader or Mi Account
If, after a reset or firmware, the phone requires a password from your Mi Account (Mi Account Lock) and you don’t remember it, that’s a separate problem. Xiaomi blocks devices after a hard reset if the account was previously linked.
Methods of unlocking:
- 🔑 Enter the correct username/password from Mi Account (try to restore via account.xiaomi.com).
- 📧 If an email or phone number is linked, ask for a recovery code.
- 🛠️ Contact the authorized Xiaomi service center with proof of purchase (check, box.
To unlock the bootloader (Bootloader):
- Apply for unblocking through en.miui.com/unlock (You will need a Mi Account linked to your phone).
- Download the Mi Unlock Tool and follow the instructions.
- Connect your phone in Fastboot mode and wait for the unlock confirmation (can take up to 720 hours!).
Important: Do not use left-handed programs to bypass the lock – this can lead to complete data loss or blocking. IMEI.
Moisture intrusion and contact corrosion
Xiaomi Mi 9 has no official water protection (IP-certificate is missing, so even a small ingress of moisture can cause a short circuit:
- The phone stopped turning on after contact with water (even if it was dry).
- There is a smell of burning when charging.
- On the screen, artifacts or backlights work unevenly.
What to do:
- Turn off the phone immediately (if it is still responding) and remove it. SIM-map.
- Place the device in a silica gel container (shoebox bags) for 48 to 72 hours. Rice is less effective!
- After drying, try turning it on. If it doesn't work, take your phone apart and check for corrosion:
Typical corrosion sites on the Mi 9:
- 🔋 Battery contact.
- 📶 The squatting (near the squatting) SIM-tray).
- 🔌 Type-C connector and charging controller.
- 🖥️ Microchips on the motherboard (especially near the processor).
If you see a green or white coating, don't rub alcohol.
- Isopropyl alcohol 99% + softbrush.
- Ultrasonic bath (in service centers).
⚠️ Warning: If the phone starts to warm or smell like a burn after getting moisture, don't turn it on! This is a sign of a short circuit that could damage the board irrevocably.
7. When to contact the service center
Not all breakdowns can be repaired by yourself.
- 🔧 The phone does not respond to all manipulations (charging, buttons, connection to the PC).
- 🔥 There are signs of short circuit (heating, burning smell, board darkening).
- 🛠️ Replacement of chips is required (UFS, PMIC, processor).
- 🔒 You need to unblock Mi Account without access to the original account.
- 📱 Screen or touchscreen damaged (replacement requires special glue and calibration).
Average prices for repairs Xiaomi Mi 9 in 2026:
| Type of repair | Cost (rupe) | Timeline |
|---|---|---|
| Battery replacement | 1500–2500 | 1-2 hours |
| Replacement of Type-C connector | 1200–2000 | 1 day |
| Repair of the motherboard (silvering of chips) | 3000–8000 | 3-7 days |
| Screen replacement (original) | 5000–9000 | 2-3 days |
| Unlocking the Mi Account (officially) | 1000–3000 | 1-5 days |
Where to look for reliable service:
- 🏢 Authorized Xiaomi Centers (list of the mi.com/ru/service).
- 🔧 Services with good reviews on Yandex.Maps or 2GIS (look for specialization in Xiaomi).
- 🛒 Shops where you bought your phone (sometimes give you a discount on repairs).
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Before you put your phone in for repair, back up your data (if the phone is responding at all) and the service can erase information without warning!