Why Xiaomi Redmi Note 9 is Glitting: A Complete Analysis of Causes and Solutions

Xiaomi Redmi Note 9 is one of the most popular smartphones in the budget segment, but even it is not immune to software failures and hardware problems. If your phone starts to slow down, spontaneously reboot, turn off or behave inadequately, do not rush to carry it to the service center. In 80% of cases, the cause can be eliminated on your own without having special skills.

In this article, we will look at all the possible causes of glitches, from simple memory overflows to serious hardware malfunctions. You will learn how to diagnose a problem, what settings to check first, and when to really contact the wizard.

For convenience, we've created a table of symptoms with probable causes and solutions, and we've added interactive widgets to help you identify the source of the problem more quickly. FAQ-block with answers to typical situations.

1. CPU overheating: why the Redmi Note 9 brakes and turns off

One of the most common causes of glitches is overheating of the MediaTek Helio chipset. G85. This processor is prone to heat up under intense loads, and in the Redmi Note 9, the problem is exacerbated by a bad heatpast on some batches of devices. If the phone gets hot even on simple tasks (for example, watching a video on YouTube), this is a sure sign of overheating.

How to check the temperature:

• 📱 Install the app AIDA64 or CPU Monitor from Google Play.
• 🔥 Run a load test (e.g. Genshin Impact or AnTuTu benchmark).
• ⚠️ If the temperature is above 65°C is a critical indicator.

Solutions:

• 🛠️ Replacing thermopaste is a radical but effective method, and service centers do this in 1-2 hours.
• 📉 Performance Limitation: in Developer Settings (Settings) → The phone. → Version. MIUI — tap 7 times) turn on the option to limit background processes.
• 🌡️ Use a cooling cover or avoid direct sunlight.

⚠️ Warning: If the phone turns off at temperatures below 60°C, which may indicate a battery or temperature sensor malfunction, and this requires a diagnostic in the service.

2. Firmware problems: errors MIUI Android

Redmi Note 9 is working on the MIUI — It's a branded shell from Xiaomi, which is known for its bugs, and it's usually a bug that comes after updates or when you use custom firmware:

• 🔄 Self-involved reboots.
• 📵 Logo hangings MI switch-on.
• 🚫 Some functions do not work, for example, NFC or IR-blaster).

How to diagnose:

1. Check out the MIUI version in Settings → About the phone.
2. Look for information about this version bugs in forums (e.g, 4PDA or Mi Community).
3. If the phone doesn't turn on, try going to Recovery Mode (clip the power). + Loudness up).

Decisions:

Critical information: Redmi Note 9 with firmware MIUI 12.5 and above, there's often a black screen bug after unlocking, and it's because of a flaw in the display driver. MIUI 12.0.3.0 or update to the latest version (if available).

Download the official firmware from the Xiaomi website

Check the battery (minimum 50%)

Make a backup of data through Mi Cloud or TWRP

Disable the Mi Account lock (if any)

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3. Battery malfunctions: rapid discharge and sudden shutdowns

The 5020mAh battery in the Redmi Note 9 should easily hold a charge for a day with moderate use. If the phone runs out in a few hours or turns off at 20 to 30 percent charge, it is a sign of battery degradation or a power controller failure.

How to check the status of the battery:

• 🔋 Enter the number number ##4636## → Select Battery Information.
• 📊 Install AccuBattery app to analyze charging cycles.
• 🔌 If the phone is not charging above 80%, it is a sign of battery bloating (replacement required!).

What to do:

• 🔄 Battery calibration: fully discharge your phone, then charge to 100% without interruptions.
• 🛠️ Battery replacement – if the capacity has fallen below 70% of the nominal (checked in AccuBattery).
• ⚡ Use the original ZU (18W or 22.5W). Cheap charging ruins the power controller.

⚠️ Warning: If the phone suddenly turns off at 15-50% charge and does not turn on without connecting to charge - this is a sign of a break in the battery chain.

Memory failures: why Redmi Note 9 lags and does not open applications

Redmi Note 9 was produced in versions with 3/64 GB, 4/64 GB and 4/128 GB of memory. Even in the maximum configuration, users face a shortage of RAM and overflow of the drive:

• 🐢 Slowing down animations and lags when switching between applications.
• 🚫 Errors of the type "Application stopped".
• 📱 spontaneous closure of background processes (for example, music ceases to play).

How to free up memory:

1. Remove the app cache: Settings → Annexes → Select an application → Clear the cache.
2. Transfer files to SD-Card (if supported) Redmi Note 9 can use cards up to 512GB.
3. Turn off autoloading of unnecessary apps: Settings → Battery → Auto-start.

Extended methods:

• 🔧 Enable Advanced Memory Mode in Developer Settings (force_msaa_4x — Not recommended for low-level games).
• 📦 Use Lite versions of apps (e.g. Facebook Lite, Messenger Lite).
• 🗑️ Clean the Download folder regularly and DCIM/Thumbnails (Here are the miniatures of the photos).

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If the phone is slowing down, but there is enough memory – check the background processes through Settings → Developer → Process statistics: Sometimes virus applications are disguised as system applications and loaded. CPU.

5 Network problems: Wi-Fi, mobile internet or Bluetooth are not working

Communications module failures are a common problem with the Redmi Note 9, especially after updates MIUI. Typical symptoms:

• 📶 Mobile Internet only works in the mode 2G.
• 🔌 Wi-Fi is connected, but the speed is extremely low.
• 🔊 Bluetooth is permanently disabled when playing music.

Causes and solutions:

If network problems have occurred after the update MIUI, try:

1. Reset network settings: Settings → System → Reset settings → Reset network settings.
2. Turn on Flight Mode for 30 seconds, then turn off.
3. Check it out. IMEI (Type *#06#. If Null is displayed, you need to restore it with Engineer Mode.

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If the network settings are reset, the problem persists, it may indicate a hardware malfunction of the antenna module, in which case only repairs will help.

6. Display glitches: flickering, broken pixels, sensor not working

Redmi Note screen 9 (permit 2340×1080, IPS LCD) subject to several typical problems:

• 🖥️ Screen flickering at low brightness.
• 🎨 Broken pixels (black or colored dots).
• 👆 The sensor part is not working (usually at the edges).

Causes and solutions:

• 🔦 Blink: Turn on Auto Brightness or turn off Night Mode in Settings → Display. If the flicker is left, it's a backlight defect (replacement of screen required).
• 🎯 Broken pixels: try to “overclock” them with the Dead Pixel Test app (not always helpful.
• 📱 Sensor's not working: check if there's a bubble shield, and if the sensor is the problem, you need to change the touchscreen.

To diagnose the display:

1. Run the screen test via ##6484## (on some firmware).
2. Check the reaction to touch in Safe Mode (clip the power supply) → Hold the power down. → Choose Safe Mode).

⚠️ Warning: If after the phone falls, colored stripes or liquid crystals appear on the screen, this is a sign of a plume rupture or damage to the matrix)!

7. Viruses and Malware: Hidden Threats

Redmi Note 9 is often a target for viruses, especially if you install apps from third-party sources.

• 📲 Appearance of unfamiliar apps on the menu.
• 💰 Debiting money from the account (if a bank card is tied).
• 📊 A sharp increase in traffic consumption or battery charge.

How to check and remove viruses:

1. Install Malwarebytes or Dr.Web Light and perform a full scan.
2. Check the list of installed applications: Settings → Annexes → All apps: Delete suspicious ones (e.g., with Chinese names).
3. Disable installation from unknown sources: Settings → Privacy → Special permissions → Install unknown applications.

If the virus blocks access to the settings:

• 🛡️ Download your phone to Safe Mode and remove the malware.
• 🔄 Perform reset to factory settings (data will be deleted!).
• 📱 If nothing helps, reflash your phone via Fastboot.

8. Hardware malfunctions: when you need the help of a master

If all software methods have been tried, but the phone continues to glittle, the problem may lie in the hardware.Typical hardware malfunctions of the Redmi Note 9:

• 🔌 Failure of the charging connector (the phone charges only in a certain position).
• 🎤 The microphone or speaker is not working (after falling or getting moisture).
• 📡 Bad signal reception (even with good network coverage).

Diagnosis:

When to contact the service:

• 💧 If the phone fell into the water or was exposed to high humidity (even if it is now working).
• 🔥 If the body is heated for no reason (risk of fire!).
• 🛠️ If after disassembly (for example, changing the screen) new glitches appeared.

⚠️ Warning: If you decide to disassemble the phone yourself, remember: Redmi Note 9 has a fragile battery plume!

FAQ: Answers to Frequent Questions