Xiaomi Redmi Note 8T screen goes out when you call: all the reasons and how to fix

Introduction: Why this happens and whether to worry

You call the Xiaomi Redmi Note 8T, you hold your phone to your ear, and the screen suddenly goes out. The call goes on, but it becomes impossible to control it: you can't turn on speaker, switch to speaker or complete the call. The situation is familiar? This is one of the most common complaints of Redmi Note 8/8T owners, and the reasons can be hidden in hardware malfunctions and software failures.

In most cases, the problem is not critical and solved without visiting a service center, but if the screen goes out unpredictably - 2 seconds after the start of the call, then 20 - or is accompanied by other symptoms (for example, spontaneous reboots), this can indicate serious problems. In this article, we will analyze all possible causes, from banal to rare, and give clear instructions for eliminating each of them.

Note: if your Redmi Note 8T fell before the problem or was in the water, most likely, the fault is mechanical damage to the proximity sensor or the plume of the display. In other cases, you should start with software methods - they are less expensive and often give results.

1. The proximity sensor: how it works and why it fails

The main reason the screen goes out when you call is because the proximity sensor is not working properly, and it's located at the top of the screen (near the front camera) and it's responsible for turning off the display when you bring the phone to your ear, so you can prevent accidental taps during a conversation. The Redmi Note 8T uses an infrared sensor that can fail for several reasons:

• 🔍 Sensor pollution: Dust, greasy prints or protective film block infrared signal.
• 💥 Mechanical damage: A phone hit or fall could have displaced the sensor or damaged its contacts.
• 🔄 Calibration failure: after update MIUI or resetting the sensor may work unstablely.
• 🛠️ Wear over time: in models 2019-2020 release sensors often fail after 2-3 years of operation.

To check the operability of the sensor, use the service code:

1. Open the Phone app.
2. Enter the combination: ##6484## (or #4636## → Equipment Testing).
3. Select Proximity Sensor (Proximity Sensor).
4. Close the sensor with your hand - the value should change from 5.00 cm to 0.00 cm. If there is no reaction or the readings jump chaoticly, the sensor is defective.

⚠️ Warning: If the sensor shows 0.00 cm even when the phone is lying on the table, it means sticking contacts - a sign of moisture or oxidation of the board.

2. Software failures: MIUI, firmware, and application conflicts

If the proximity sensor is working, but the screen is still going out, the software is to blame. In the Redmi Note 8T, the most common problem is:

• 📱 An outdated version MIUI: firmware MIUI 12.5 There were bugs with sensor control during calls.
• 🔄 Failed update: if the phone was updated “over the air” with a weak Wi-Fi signal, files could download with errors.
• 🤖 Application conflict: Some programs (such as Truecaller, DualSpace, or modified launchers) take control of the screen.
• 🧹 Clogged cache: system cache files can block correct operation of sensors.

How to diagnose a programmatic cause:

1. Check out the MIUI version: Settings → About Phone → MIUI version. If it is older than 12.5.3, an update is required.
2. Run your phone in safe mode (hold the power button → Safe Mode). If the problem disappears, the third-party app is to blame.
3. Clear the cache: Settings → Applications → App management → Phone → Storage → Clear the cache.

Critical information: There was a bug in MIUI 11 firmware for the Redmi Note 8T that would turn the screen off when you call if Read mode is turned on, and check if it's activated in the notification curtain.

3. Energy saving and optimization settings

Aggressive power saving settings in Xiaomi can cause the system to force the display to turn off during a call to "save charge."

• 🔋 You are using ultra-economic or super-saving mode.
• ⚡ Optimization for the Phone application is enabled.
• ⏳ The screen settings have a minimum waiting time (10 seconds).

How to remove unnecessary restrictions:

1. Go to Settings → Battery and Performance → Battery Settings
2. Select Mode Choice and set Balanced (not Economical!).
3. In Battery Optimization, find the Phone app and turn off optimization for it.
4. In Settings → Screen → Sleep mode set a value of at least 30 seconds.

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If the problem occurred after the MIUI update, try to roll back to the previous version via Fastboot. Instructions for the Redmi Note 8T are available on the 4PDA forum in the firmware theme.

Mechanical damage: plume, display, board

If the software methods didn't help, it's time to consider hardware faults.The Redmi Note 8T is the most vulnerable:

• 📱 Display plume: when falling or opening the lid often, it can rub or move away from the connector.
• 🔌 Approximation sensor connector: oxidation or poor contact leads to false positives.
• 💧 Moisture intrusion: Even after drying, corrosion on the board can manifest itself after months.
• 🔨 Screen damage: cracks in sensor area block its signal.

How to diagnose a hardware problem:

1. Light a flashlight on the top of the screen at an angle, and if you see rainbow swelling under the windows, it's a sign of the plume's detachment.
2. Lightly press the proximity sensor area (not the screen, but the phone frame!) If the screen starts to blink or go out, the contact problem is.
3. Check if the battery is bloated: Settings → Phone → Battery condition. Bloating can press on the display plume.

⚠️ Warning: If your phone falls into water or works in the rain, don't dry it with a hair dryer or rice, it will speed up corrosion.

Conflicts with SIM-map-and-net

Rarely, but it happens: the screen goes out due to problems with the screen. SIM-This is because when you call, the system switches to the modem, and if there's a failure in the chain, it can cause the interface to freeze:

• 📶 The screen is only turned off when calling through 2G/3G, 4G (VoLTE is working normally.
• 🔄 Before going out, an icon appears on the screen! or × near the network indicator.
• 📱 The phone will spontaneously switch to mode 2G.

Decisions:

1. Switch to the switch. 4G (VoLTE: Settings → SIM-maps and mobile networks → [Yours. SIM] → Preferred type of network → 4G.
2. Turn off Improved Call Quality (if enabled): This mode sometimes conflicts with sensors.
3. Try calling someone else. SIM-If the problem is gone, it's your main card (possibly chip damage).
4. Reset network settings: Settings → System and device → Reset settings → Network reset.

6. Solutions for advanced: debugging and manual settings

If standard methods don’t work, you can try manual settings through the Engineering Menu or ADB. These methods require caution, but often help in advanced cases.

Method 1: Calibration of the sensor through the engineering menu

1. Enter the code: ##36446337## (or #4636###).
2. Choose Hardware Testing → Proximity Sensor.
3. Press Calibrate and follow the instructions on the screen.

Method 2: Disable the proximity sensor via ADB (if it is completely faulty):

adb shell settings put system proximity_delay 2500


adb shell settings put system proximity_distance 5.0

These commands will increase the sensor delay and change the sensitivity threshold. Once you enter, restart the phone.

Method 3: Manual firmware updates via Fastboot

If the problem has occurred after the update "over the air", download the full firmware for the Redmi Note 8T (codename willow) from the official website en.miui.com and scroll through the Mi Flash Tool.

⚠️ Attention: Before use ADB or by firmware via Fastboot, back up through Settings → Additionally. → Backup and reset: Wrong commands can lead to a brick (completely inoperable) phone.

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If you are not sure about your ADB or firmware skills, you should contact the service. Wrong actions can deprive the phone of warranty (if it is still valid).

7. When there's only a service center left

If none of the methods worked, most likely, the problem is hardware and requires professional repair.

• 🔧 The screen goes out even in the engineering menu (meaning the board or plume is faulty).
• 💧 The phone fell into the water or worked in a humid environment (to clean the board).
• 🔥 Artifacts (strips, flickers) appeared on the screen - this is a sign of damage to the matrix or graphics chip.
• 📉 After a fall or impact (even if there is no external damage, the plume could move away).

What to do in the service:

• 🔍 Diagnostics of the proximity sensor and its replacement (cost: ~800–1500 ₽).
• 📱 Replacement of the display plume (cost: ~1500–2500 ₽).
• 💻 Replacement or replacement of the network module (if the problem is SIM-map).
• 🔋 Replace the battery (if it swells and presses on the board).

Average repair costs for Redmi Note 8T in 2026, 1,000 to 4,000 ₽, If the phone is warranty-free, don't hack it yourself, it will void the warranty.

FAQ: Frequent questions about the problem