When your Xiaomi Redmi 4X suddenly stops responding to a charger connection, it can be taken by surprise at the most inopportune moment: The screen stays black, the indicator doesn't light up, and the phone doesn't give signs of life, even if you've just used it by 20%.This is a common problem for this generation of devices that can be caused by both a software glitch and a serious hardware defect.
Before you bring your gadget to the service center, you should do your own diagnostics, and often the cause is trivial oxidation of contacts or damage to the cable, which is easily eliminated at home, but ignoring the symptoms can lead to a complete failure of the power controller, which will require expensive repair of the motherboard.
In this article, we will take a look at all the possible causes of the lack of charging on the Redmi 4X, from simple software "glitch" to complex soldering chips, learn to distinguish between software errors of the MIUI system and physical battery damage, and learn when self-intervention is safe and when it is better to stop.
Diagnostics of external elements and accessories
The first step should always be to check the peripherals, because they are the ones that fail most often. USB cables are subject to constant mechanical stresses: twisting, stretching and bending, which over time leads to internal rupture of the conductors. Even if the wire looks whole, the integrity of the vein transmitting current can be broken inside it, making charging impossible.
The power supply is a second candidate for testing. Unstable grid voltage or surges could have damaged its internal circuitry, causing it to stop delivering the required 2-ampere current required to charge the Qualcomm Quick Charge. Try connecting the phone to a computer or other adapter to rule out a power source malfunction.
The Micro-USB connector on the smartphone itself is particularly noteworthy, and in the pockets of clothing it is often clogged with pile and dust, which are compressed and block the plug from entering fully, and if the cable is not inserted fully or dangling, contact with the conductive tracks is not closed.
⚠️ Warning: Do not use metal objects (needles, pins) to clean the connector unless you have turned off the battery.Closing the contacts can permanently kill the charge controller.
For safe cleaning, it is better to use a wooden toothpick or plastic spatula, carefully cleaning garbage from the depths of the port, and also check if there are traces of oxidation or moisture inside the connector that may have gotten there when using the phone during the rain.
- 🔌 Check the cable for fractures and try to replace it with a known working analogue.
- ⚡ Test charging from different sources: Power Bank, computer, car charging.
- 🧹 Carefully clean the charging port from dust and pile with compressed air or a dry brush.
Software failures and controller freeze
Sometimes the problem is not hardware, but software. Android, in conjunction with the MIUI shell, may encounter a driver error that controls energy, causing the phone to "think" it's charged, or to block the current from flowing because of a false signal that it's overheating or short circuiting.
A common cause is the power controller itself, which is a chip that regulates all the processes involved in the battery, and when a power surge or a software conflict occurs, it can go into protective mode and stop running current onto the battery, in which case a standard reboot through the menu may not help, because the system does not respond to touch.
To solve this problem, there is a forced reboot method that resets static electricity and restarts the controller, you need to press the power button and hold it for a long time, sometimes up to 20-30 seconds, and if the screen flashes with the MI logo, the problem was software.
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If the phone is discharged to zero, leave it charging for 30-60 minutes, even if the screen is not responding.Lithium polymer batteries take time to dial up the minimum charge to turn on.
In some cases, the culprit is a specific application that mismanages the background and prevents the phone from going to sleep, causing overheating and subsequent blocking of charging. Check the battery usage statistics in the settings to identify such "eaters" of energy.
Hardware problems: plume and charging connector
If software methods didn't work, it's probably a physical breakdown: In the Redmi 4X, the charging connector is soldered directly on the motherboard, rather than being put on a separate pallet board, as in many other smartphones, which makes repairs more difficult, as replacement requires soldering skills and a thermo-air station.
A common problem is rotting or loosening the contacts of the Micro-USB connector itself. Due to constant connections and disconnections of the cable, the soldering breaks, and the contact disappears. Visually, this may be invisible, but with a slight movement of the cable, charging appears and disappears.
It is also worth inspecting the plume connecting the main board to the lower board (where the microphone and speaker are located). 4X The mainland connector, the plume, transmits signals, and if it's damaged or oxidized, it can affect the periphery, but it's often the connector itself that's the fault. BMS-battery-board.
| Symptoms. | Probable cause | Difficulty of repair |
|---|---|---|
| Charging occurs only at a certain position of the cable. | Broken Micro-USB connector | High (needs ration) |
| The phone says, "Put the charger on." | Unstable current or poor cable | Low. |
| The indicator is burning, but the percentage does not increase | Battery wear or calibration | Medium |
| The phone is warming up in the off state | Short circuit in the food chain | Tall. |
To replace the connector, you need to completely disassemble the device, remove the battery and the screen. Be careful: the display plume in the Redmi 4X is quite fragile and can break if you sloppy handle, which will lead to the need to replace the entire screen.
Battery wear and malfunction
Lithium polymer batteries have an average lifespan of 2-3 years of active use. If your Xiaomi Redmi 4X has been in use for several years, the chemical cell is probably exhausted. The battery loses capacity, the voltage drops below a critical level, and the controller blocks charging to avoid bloating or ignition.
One of the signs of a dying battery is that it's going to have a sharp spike in its percentage of charge, and it might go 40 percent off, then suddenly turn off, and when you plug it in, it's going to show you 1 percent or 100 percent, which means that the voltage performance is broken, and the battery can no longer hold the load.
Battery bloating is a critical symptom that requires immediate replacement, and if the back of the phone starts to move away or the screen rises slightly, do not attempt to pierce the battery or charge the device further.
☑️ Diagnostics of the battery
Replacing the battery in the 4X is relatively simple, since the back cover is removable. However, to get to the battery, you will have to unscrew many screws and remove metal screens. It is recommended to use original batteries or proven analogues from brands like Nohon or Deji, since cheap Chinese copies often have a real capacity of 2 times less than the declared one.
Failures of the power controller and the charging circuit
The most serious problem faced by Xiaomi owners is the failure of the power controller (CP) or charging circuits on the motherboard, which can occur due to the use of poor-quality chargers, power surges in the network or moisture.
In Redmi 4X, the charger is a chip that distributes currents. If it burns, the phone can only turn on from charging, but not charging, or completely ignore the connection, and the diagnosis of such a malfunction is possible only in a service center using a multimeter and a laboratory power supply unit.
Often, the controller burns up capacitors or resistors in the band, and the wizard can tell by the current consumption: if the phone eats 0 Amps or vice versa, it goes into a short circuit (KZ) immediately when the voltage is applied, the problem is in the board.
⚠️ Attempts to charge the phone with a faulty power controller "folk methods" (warming up, freezing) can lead to complete burnout of the processor, after which recovery will be economically inexpedient.
Repairs require skilled soldering under a microscope, and it is almost impossible to restore the charging circuit on your own, without experience or equipment, and the cost of repairing it can be a significant fraction of the cost of a used device.
Resetting and calibration of the battery
If (iron) is working but the phone is not behaving properly, software calibration is a process that helps the system re-determine the actual battery capacity and correctly display percentages. For the Redmi 4X, this is true if charging is going on, but the percentages will jump.
One method is to fully discharge and charge the phone until it is completely turned off, then turn it on and discharge it again until it stops turning on, then, without turning on the phone, charge it to 100% (and hold it for a couple of hours).
A more radical method is factory reset, which will delete all the data, but can fix errors in the system's energy-consumption files, and make sure to back up your contacts and photos before doing so.