Why Xiaomi Redmi 9 is in trouble: a full analysis of the causes and solutions

What to do if your Redmi 9 doesn’t work the way it should

Xiaomi Redmi 9 is one of the most popular budget phones, but even it is not immune to failures. Users often face situations when the device begins to “glut”: suddenly brakes, overheats, does not charge or exhibits other oddities, the reasons can be hidden in software errors and hardware malfunctions.

This article will help you understand why your Redmi 9 is having problems and what to do about it, and we will analyze the 10 most common symptoms, from basic (like slow work) to severe (sudden shutdowns), and offer step-by-step solutions, from rebooting to replacing components.

If your smartphone is still under warranty, do not try to disassemble it yourself - this can lead to loss of warranty obligations. Otherwise, follow the instructions below, but remember: any manipulation of iron you perform at your own risk.

1.Why Redmi 9 brakes and lays

Slowdown is the most common complaint of Redmi 9 owners, and the reasons can range from overloaded memory to outdated firmware, to start with the simplest of them all: software factors.

The first thing to check is the memory space, and if you have less than 10 percent of internal storage, the system slows down, delete unnecessary files, cache applications, or transfer data to a memory card, and pay attention to the background processes: some applications (especially messengers and social networks) consume a lot of resources even when folded.

• 📱 Close all background apps through the multitasking menu (swipe up and hold).
• 🔄 Reboot your smartphone – it cleans up RAM.
• 🗑️ Clear the cache in the settings (Settings) → Warehouse → Clear the cache).
• 🔧 Turn off animation in the developer settings (Settings) → The phone. → Version. MIUI (tap 7 times) → Developer settings → Scale of window/transition animation → select Off.).

If the brakes are not gone, the problem may be in the firmware. → The phone. → System Update. Xiaomi regularly releases patches that fix performance errors. If there are no updates, try resetting to factory settings (don't forget to make a backup!).

2.Overheating: When Redmi 9 gets hot

Overheating is a common problem for budget smartphones, and the Redmi 9 is no exception. The normal operating temperature of the processor is up to 40-45.°C, but if the body heats up so that it is unpleasant to hold in your hand, it is cause for concern.

The main causes of overheating:

• 🔥 Intense load: games, video editing, streaming in high resolution.
• 🔋 Charging and use simultaneously (especially with fast charging).
• 🌡️ High ambient temperature (for example, the phone lies under direct sunlight).
• 🛠️ Faulty battery or cooling system (dust in the radiator, dried thermopaste).

If the phone is warming up even in standby mode, it could indicate a hardware malfunction, for example, a bloated battery not only overheats, but can damage the motherboard, in which case the only solution is to replace the battery.

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To cool your phone quickly, turn it off and put it in the shade for 10-15 minutes. Don't use the refrigerator - a sharp temperature drop can damage the capacitors!

3. Charging problems: not charging or charging too slowly

If your Redmi 9 has stopped charging or has been doing so for too long, there may be several reasons.

1. The cable or adapter is damaged, check if there are any crevices or bare wires on the wire, try charging the phone with another cable.
2. Contaminated connector. USB-C. Dust and debris can prevent normal contact. Clean the connector with a wooden toothpick (not metal objects!).
3. The charging port is faulty. If the cable is not holding well or the phone is only charging in a certain position, it may be that the connector is shattered or the contacts have oxidized.
4. Battery problems: If the battery is worn out (capacity has dropped below 70%), it may charge slowly or hold no charge.

Also check your phone settings:

• 🔌 Turn off optimized charging (Settings) → Battery → Optimized charging).
• ⚡ Enable fast charging (if supported by your adapter).
• 📵 Put your phone in airplane mode while charging – this will speed up the process.

Try a different cable and adapter|

Clear the connector. USB-C dusty|

Check the phone for moisture (indicator in the tray) SIM-map)|

Run the battery test through the engineering menu (#4636##)|-->

If nothing works, maybe the power board or the charging controller is faulty, and you can't do without repairs.

4. Self-reboot and shutdown

If Redmi 9 suddenly shuts down or restarts for no apparent reason, it could be due to:

• 🔋 Discharged or faulty battery (phone turns off at 20-30% charge).
• 🛠️ Processor overheating (protective shutdown at critical temperature).
• 🤖 Firmware failure (especially after update).
• 💥 Short circuit on the motherboard (often after falling or getting moisture).

For diagnosis:

1. Check the error logs through the engineering menu (#4636## → Battery information).
2. Launch your phone in Safe Mode (hold the power button) → "Safe Mode. If the reboots have stopped, one of the installed applications is to blame.
3. Test the battery (see spoiler above).

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If the phone turns off at 20-40% charge, it's a sure sign of battery wear and tear, and replacing the battery will solve the problem 90 percent of the time.

If the reboots occur even after the reset, the hardware is likely to be the problem, for example, the battery plume could have left or the power chip damaged after the fall, in which case only repairs will help.

5 Sensor problems: does not respond to touch

A broken sensor is one of the most unpleasant malfunctions, and the causes fall into two categories:

• Software: firmware failure, application conflict, calibration error.
• Hardware: damage to the plume, crack on the display, ingress of moisture.

First, try recalibrating the sensor:

1. Go to the engineering menu: ##6484###.
2. Select the Touch Screen Test.
3. Follow the instructions on the screen (touch the points for calibration).

If the calibration didn't help:

• 🔄 Reboot the phone.
• 📱 Reset the settings to factory.
• 🛠️ If the sensor doesn't respond at all (even when it's rebooted), it's likely that the display module or the plume is damaged, and you need to change the screen.

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If the sensor is not responsive in certain areas (e.g., the edges), it can be caused by mechanical damage or moisture falling under the screen. Don't delay repairs - the problem will worsen over time!

6.No sound: speakers and microphones are not working

Lack of sound is another common problem, and it can manifest itself in many different ways.

• 🔈 The speaker does not make sounds (neither in calls nor when playing music).
• 🎤 The microphone does not transmit the voice of the interlocutor.
• 🔊 The sound is there, but it is quiet or distorted.

First, check the basic settings:

• Make sure the sound is not turned off (volume buttons, Do Not Disturb mode).
• Check if the headphones are connected (sometimes the phone “hangs” in the headset mode).
• Clean the headphone jack from dust (use a toothpick).

If the sound is not only in the calls:

• 📞 Check if the speaker mode is activated.
• 🔧 Go to Settings. → Sound. → Call quality and select HD-voice (if available).
• 🛠️ If the microphone is not working, the plume may have gone out or the audio codec may have failed.

To diagnose hardware problems:

1. Connect the headphones – if there is sound in them, the problem is in the dynamics.
2. Call another phone and see if the person you are talking to can hear you.
3. If neither the speaker nor the microphone is working, the audio chip on the motherboard may have been damaged.

7. Network problems: not catching mobile Internet or Wi-Fi

If Redmi 9 stopped connecting to a mobile network or Wi-Fi, the reasons could be in both settings and hardware.

Mobile Internet (4G/3G):

• 📶 Make sure that mobile data is enabled (Settings) → SIM-maps and mobile networks).
• 🔄 Reboot your phone or turn on/off the plane mode.
• 📡 Check if there is a traffic limit.
• 🛠️ If the network does not catch at all, it is possible that the modem or antenna plume is defective.

Wi-Fi:

• 🔌 Reboot the router.
• 📵 Forget the network and connect again (Settings) → Wi-Fi → Press the net. → Forget it).
• 🔒 Check if the restriction is worth the MAC-router address.
• 🛠️ If Wi-Fi is not turned on at all, the Wi-Fi module may have failed.

If network problems have occurred after the firmware update, try rolling back to the previous version or resetting the network settings (Settings) → System system → Resetting settings → Resetting network settings).

8 Camera not working: black screen or errors

Camera problems on Redmi 9 can be different: black screen, blurred image, "Can't connect to camera" error.

• 📸 Camera app crash (often after an update).
• 🛠️ Damage to the camera plume (for example, after falling).
• 🔧 Conflict with other applications (e.g., video shooting applications).
• 💥 Hardware malfunction of the camera module.

Try the software solutions first:

1. Clear the cache and data of the camera app (Settings) → Annexes → Camera. → Warehouse → Clear the cache/data).
2. Reboot the phone.
3. Install a third-party application for shooting (such as Open Camera) and check if the camera is running through it.

If the camera is still not working:

• 🔄 Reset your phone settings to factory.
• 🛠️ If the problem persists after the reset, it's likely that the camera plume or the module itself is damaged, and that's where repairs are needed.

If the camera only makes a bug in certain apps (like Instagram or TikTok), the problem isn't the hardware, it's the software conflict. Try updating the app or giving it all the permissions you need.

FAQ: Frequent questions about Redmi's problems 9