The situation of your favorite smartphone suddenly going out and refusing to react to any action is always panic-provoking.The Xiaomi Redmi 4, released in 2016, has established itself as an "unkillable" device, but even legendary reliability has a limit.If the screen is out, the indicators are silent and the power button doesn't even cause vibrations, it doesn't always mean a fatal motherboard breakdown.
Often the problem lies in a software failure, deep battery discharge or sticking button on. Before you carry the device to the service center, you need to conduct a number of diagnostic procedures that will help to identify the true cause of the malfunction. In this article, we will discuss in detail all possible scenarios and methods of restoring the health of your gadget.
It's important to understand that hardware failure and software error require fundamentally different approaches. Don't rush to disassemble the case if you have a chance to solve the problem with software methods. Let's go through the steps that will help bring your device back to life.
Primary diagnosis and exclusion of banal causes
The first thing to do when Redmi 4 doesn't respond to the power up is to check the basics. Often users forget about them in the heat of the moment. Make sure the charger is working, the cable is free of clamps, and there's a voltage in the socket. Try using another power adapter, preferably original or certified.
Sometimes the phone just goes to sleep because of the system freeze, and in this state, the MIUI operating system does not handle button presses. To get out of this state, you need to force the reset. Press the on button and hold it for 10-15 seconds. If the Mi logo appears on the screen, then the device just hovers.
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Try connecting your phone to your computer through USB-If the PC makes a new device connect sound, the motherboard is alive, and the problem is probably in the display or the plume.
Pay attention to the charge indicator (if any) or the screen behavior when connected to charging. Even a faint red light can indicate that the battery is completely discharged and needs time to store energy before starting.
Problems with battery and charging
The battery is a consumable, and in models released a few years ago, its life could run out. If the Redmi 4 was idle for a long time, the voltage in the cells could fall below a critical threshold, and the power controller blocks charging for safety reasons.
In this case, standard charging may not start immediately. Leave the phone connected to a powerful power supply (at least 1-2 Amps) for 30 to 60 minutes, even if the screen remains black.
⚠️ Attention! If the phone starts to heat up in the camera or lower part of the case when you connect to charging, immediately turn it off. This is a sign of a short circuit inside the battery or on the board, which can cause ignition.
Check the charging connector (Micro-USB). In older models, it is often loosened or clogged with dust and pile from your pockets. Carefully, using a wooden toothpick or plastic shoulder blade, clean the port. Metal items are not recommended to use so as not to close contacts.
If you have a multimeter, you can check the voltage on the battery contacts by first disassembling the back cover. The normal voltage for lithium polymer batteries is about 3.7-4.2 Volts. If the multimeter shows 0 or values below 3.0 V, the battery will most likely have to be replaced.
Forced reset and discharge methods
When simple methods don’t work, you need to resort to more radical measures: button combinations allow you to interact with the bootloader and recovery mode even when the black screen. For Xiaomi Redmi 4, several combinations are relevant.
The first way is to enter Fastboot mode. Turn off your phone (if it's on) or wait for full discharge, then press both the Power and Volume Down buttons at the same time. Hold them until you see an image of a hare repairing an android, or a vibration. If the phone responds to this combination, then the screen and touchscreen are probably working, and the problem is the OS boot.
☑️ Button diagnostics
The second way is to try to log in to Recovery Mode. Press the Power and Volume Up buttons. If the phone vibrates and the language menu appears, you can try resetting to factory settings. To do this, select Wipe Data. Remember, this will delete all your files, photos and contacts.
What to do if the Recovery menu is in Chinese?
If the phone is in Fastboot or Recovery mode but doesn’t boot normally, the problem is that system files are damaged or applications conflict, and then flashing the device through the computer will help.
Diagnostics via computer and Fastboot mode
Connecting to a computer is one of the most informative diagnostic methods, and if the phone doesn't turn on, but when you press the power button and the volume down, the computer makes a connection sound. USB-The system will define the device as an Android Bootloader Interface or simply an unknown device.
To work with the phone in this mode, you will need the Mi Flash Tool or ADB/Fastboot utilities. Even if the phone screen is black, the computer can see it in Device Manager. Check the USB Controllers or COM Ports section in Windows Device Manager after you connect.
| Mode of work | Button combination | PC reaction | Status of device |
|---|---|---|---|
| Normal. | Short press. | Defined as a media device | Corrected. |
| Fastboot | Food + Volume Down | Android Bootloader Interface | Ready for firmware |
| Recovery | Food + Volume Up | Not determined (usually) | Reconstruction regime |
| EDL (9008) | Special combination/disassembly | Qualcomm HS-USB QDLoader 9008 | Deep discharge/Repair |
If a computer sees a phone in Qualcomm HS-USB QDLoader 9008 mode, it means that the device is in emergency boot mode. This often happens when a firmware failure or a serious bootloader failure occurs, in which only low-level firmware through a Xiaomi developer account is possible.
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If the computer detects the phone in any mode (even as an unknown device), the motherboard is most likely intact, and the problem is solved by flashing or replacing the display.
Hardware malfunctions: display and plumes
The most insidious problem that Redmi 4 owners face is the failure of the display module when the phone is working. The device can work, make notification sounds, vibrate when you call, but the screen will remain black, this often happens after falls or heavy pressure.
You can test this hypothesis by calling the number of the SIM card installed on the phone, and if there's a beep, and then the call sound, but the screen doesn't light up, the problem is in the display or its plume, and in some cases, it helps to carefully press the top of the screen (where the train is connected), but this is a temporary solution.
⚠️ Attention! Redmi 4's disassembly requires care. The back cover is plastic, but it can crack if you open it in a clumsy way. The display plume and touchscreen are very thin and easily torn when you tweezers.
It's also worth checking the connectors on the motherboard, and if you hit them hard, the plume could just move away from the connector, and if you're skilled in repairing, remove the back cover and reconnect the display and battery plumes, and often that returns the image.
Device firmware and loader recovery
If the hardware is fine, but the phone goes into an endless bootloop or hangs on the Mi logo, you will need a flashing. For Xiaomi Redmi 4 (codename prada for Prime or oak for standard), there are two types of firmware: Fastboot and Recovery.
You'll need to download the firmware image from the official Mi Flash website. Unpack the archive to the root of the C drive so that the path is short (e.g., C:\rom). Run the Mi Flash Tool, select the firmware folder and press the Refresh button. If the phone is identified, the Flash button will become active.
Example of a path to a firmware file:
C:\xiaomi\prada_global_images_V10.2.3.0.MBGMIXM\imagesIt is important to choose the correct firmware mode at the bottom of the program window: Clean All (full cleaning) or Clean All and Lock** (clean and lock the bootloader). To save the "brick" it is better to choose Clean All. The process will take from 200 to 600 seconds.
Firmware error
When professional repairs are needed
Unfortunately, not all problems can be solved at home. If the phone does not respond to charging, does not vibrate, does not emit sounds and is not detected by the computer in any of the modes, there is likely a failure of the components of the motherboard.
The most common reasons for such breakdowns in Redmi 4:
- 🔌 Breaking the supply chains - requires vertebrating the circuit and restoring the tracks.
In such cases, self-repair without a soldering station, microscope and circuits can finally finish the device, it is better to contact a specialized service, where they will conduct an accurate diagnosis.