Your Xiaomi Redmi 9 has stopped responding to taps, the screen is black, and the charging indicator is not on? This problem is familiar to many owners of budget Xiaomi smartphones, especially after 1.5-2 years of active use. The reasons can range from a trivial battery discharge to serious hardware malfunctions. In 70% of cases, the device is able to “reanimate” yourself without the help of a service center.
In this article, we’ll look at all possible scenarios, from basic charging checks to Fastboot flashing or component replacements, how to tell a software failure from hardware damage, when you should try to repair your smartphone with your own hands, and when it’s best to carry it right into the workshop, and focus on the specific Redmi 9 “diseases” associated with the power controller and MIUI firmware.
1. Diagnostics of the problem: why Redmi 9 is not included
Before you get into action, it’s important to determine exactly what you’re dealing with.The Xiaomi Redmi 9 may not turn on for two main groups of reasons:
- 🔋 Power problems: discharged battery, faulty cable/charger, damaged connector USB-C charger.
- 📱 Software failures: “hang” after the update, damage to the boot partition, application conflict.
- 🛠️ Hardware malfunctions: failure of the motherboard, collapse of battery contacts, damage after falling or getting moisture.
Start with the simplest, power check, connect your smartphone to the original charger (or at least to the 5V/2A power supply) and note:
- 🔌 Charging indicator: is the red/orange LED on? If so, the battery takes charge, the problem may be in the software.
- 🔥 Heating the case: if the smartphone is very warm when connected to charging - this is a sign of a short circuit or a malfunction of the controller.
- ⚡ Power button hold reaction: try to hold the Power for 10 to 15 seconds. Vibration or unlock sound? So it's the display or the plume.
If you don't react after an hour of charging, move to the next section. If the light is on but the screen is black, try a hard reset (described below).
⚠️ Note: Do not use left-handed chargers with output current above 2.4A — This could damage the Redmi 9’s power controller, which is already a weak spot.
2 Hard Reset and Recovery Mode Entry
If your smartphone is responding to charging (the indicator is on), but it doesn't turn on, try hard reset first. This procedure clears the cache and temporary files that could block the system from booting. For Xiaomi Redmi 9, the algorithm is:
- Turn off the smartphone from charging.
- Press the Power + Volume Up buttons for 10-15 seconds.
- When the Mi logo appears, let go of Power, but keep holding Volume Up until you see the Recovery Mode menu.
From the recovery menu, select Wipe Data (use volume buttons for navigation and Power for confirmation). If the reset is successful, restart the device via Reboot. If the Recovery menu does not appear, proceed to the next method.
Disconnect the charger
Power + Volume Up for 10+ seconds
Wait for the vibration or the Mi logo
Choose the menu for Wipe Data → Wipe All Data
Confirm the reset and reset-->
If the smartphone still does not turn on after reset, but reacts to buttons, the problem may be in the firmware, in which case the firmware through Fastboot (described in section 5) will help.
⚠️ Warning: Recovery removes all data on your device, including photos and apps. If you have Mi Cloud enabled, some of the data can be restored after you log in to your account.
3. Checking the battery and the power controller
Xiaomi Redmi 9 is equipped with a battery capacity of 5020 mAh, which eventually loses capacity and can completely “die” after a deep discharge. If the smartphone does not respond to charging at all (no indication, no heating), the problem is likely:
- 🔋 Battery – if it swells or its voltage drops below 3.0V, Power controller blocks charging.
- 🔌 Connector USB-C — contact oxidation or mechanical damage.
- 🛠️ Charging controller (PMIC) — Redmi 9’s typical disease after a year of use.
To check the battery:
- Connect your smartphone to charge and wait 30 to 60 minutes. If the light doesn't light up, disconnect the cable and try another power supply.
- Light a flashlight on the screen at an angle - if the image is barely noticeable, the problem is in the backlight or plume of the display.
- Shake your smartphone -- is there a characteristic "bubbling" sound? It's a sign of a battery bloating.
If you have access to a multimeter, measure the voltage on the contacts of the battery (on the board, without disassembling the smartphone!). The normal value is 3.7-4.2V. If the voltage is below 3.0V, the battery must be “pushed” by an external power source or replaced.
How to “push” a discharged battery?
| Symptoms. | Probable cause | Decision |
|---|---|---|
| The indicator is not on, there is no reaction to the buttons | Battery discharged or power controller malfunctioned | Try to “push” the battery or replace it |
| The indicator is on, but the screen is black. | Problem with the display or plume | Connect to a PC - if determined, carry to the service |
| The smartphone warms up when charging | Short circuit in the battery or controller | Disconnect from power immediately, do not use! |
| Vibration when holding the button, but the screen does not turn on | Firmware failure or damage to the boot partition | Fastboot or EDL to Fastboot |
If you're not sure about your soldering skills, don't try to repair the power controller yourself. In Redmi 9, it's located next to the USB-C connector and requires careful microscope work.
4. Connect to PC and check through Mi Flash Tool
If your smartphone is somehow responsive to the charging connection (vibrates, the indicator is on), but it doesn't turn on, try connecting it to your computer, which will help determine whether the device is recognized by the system.
- Install Qualcomm and Mi Flash Tool drivers (you can download from the official Xiaomi website).
- Connect the switched off smartphone to the PC via USB-C cable.
- Press the Power + Volume Down buttons for 5-10 seconds to put your device into Fastboot mode.
- Open Device Manager on PC and check if Qualcomm HS-USB QDLoader 9008 or Android Bootloader Interface is available.
If the device is defined as QDLoader 9008, it means that the smartphone is in Emergency Download Mode (EDL) mode, in which case it can be reflashed even with a completely dead firmware. If it is defined as Fastboot, you can flash through standard mode.
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If your PC can’t see your smartphone, try another one. USB-cable (preferably original) or port USB 2.0 on the back of the system unit. USB 3.0 (blue) is sometimes incompatible with Fastboot mode.
For firmware via Fastboot:
- Download the official firmware for Redmi 9 (codenamed Lancelot) from MIUI Download.
- Uncancel the firmware file into a folder without Cyrillic characters.
- Open the Mi Flash Tool, select the firmware folder and press Refresh – the device should appear in the list.
- Select Clean All mode and press Flash.
It takes 5-10 minutes. Once it's done, the smartphone should automatically restart. If the firmware doesn't work, it's a hardware problem.
5. Firmware via EDL (if Fastboot doesn't work)
EDL (Emergency Download Mode) is the “last hope” for the Xiaomi Redmi 9, which is not enabled or defined in Fastboot. In this mode, the firmware is written directly to the device’s memory, bypassing the bootloader.
- 🖥️ Windows computer 7/10/11.
- 🔌 Original. USB-cable (preferably from Xiaomi).
- 📦 Firmware in.mbn format for lancelot (can be found on the forums) 4PDA or XDA Developers).
- 🛠️ Mi Flash Tool or QFil (for firmware via Qualcomm).
The firmware algorithm through EDL:
- Install the Qualcomm 9008 driver (you can download it from the Mi Flash Tool archive).
- Connect the switched off smartphone to the PC, holding the buttons Volume Up + Volume Down (on some versions of Redmi 9 you need to close the test points on the board).
- Device Manager should appear Qualcomm HS-USB QDLoader 9008.
- Open the Mi Flash Tool, select the firmware and press Flash.
It takes up to 15 minutes to run the firmware through EDL. If the process is interrupted, try again with another firmware. If that doesn't work, the problem is probably in the hardware (eMMC memory or processor).
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Firmware via EDL deletes all data without recovery. If your smartphone had important files, try retrieving them first through specialized services (such as Chip-Off).
6. Hardware malfunctions: when without service can not do
If all the software methods have been tried and the Xiaomi Redmi 9 still doesn’t turn on, the problem lies in the hardware.
- 🔋 A bloated or dead battery needs to be replaced: ~1 000–1 500 ₽.
- 🔌 Damaged connector USB-C — often fails after heavy use Repairs: ~800–1 200 ₽.
- 🛠️ Faulty power controller (PMIC) — A typical problem after a power surge: ~1 500–2 500 ₽.
- 💧 Corrosion after moisture hits - even if the smartphone didn't sink, condensate could damage the board.Diagnostics: ~500 ₽, repairs from 2,000 ₽.
Self-repair of hardware components Redmi 9 is possible only with the experience of soldering BGA-chips and specialized equipment (sweeter station, microscope, infrared hair dryer) without this you risk finally "kill" the device.
Average cost of diagnostics in the service center – 300-500 ₽. If the repair costs more than 5,000 ₽, It makes sense to consider buying a new smartphone, as the Redmi 9 has already been discontinued, and parts are becoming scarce.
7 Prevention: How to avoid recurring problems
If you have managed to restore the Xiaomi Redmi 9, follow these guidelines to avoid repeated crashes:
- 🔋 Don't drain the battery to zero. Optimal charge range: 20-80%.
- ⚡ Use only original or certified chargers (5V/2A or 9V/2A).
- 📱 Update regularly MIUI, But don’t install beta versions – they often contain critical bugs.
- 🛡️ Install a case with depreciation - Redmi 9 has weak protection against shocks.
- 💾 Backup once a month via Mi Cloud or Google Drive.
Pay special attention to the power controller - this is the "Achilles heel" Redmi 9. At the first signs of unstable charging (spontaneous shutdowns, slow charging) contact the service.
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To extend the life of the battery, turn off the function of Fast Charging in the settings: Settings → Battery → Fast Charging. This will reduce the load on the power controller.