The proximity sensor in the Xiaomi Mi 8T is a small but critical component that automatically shuts down the screen during phone calls. Its malfunction results in accidental taps, quick battery drain, or complete inability to make a call. Despite its apparent simplicity, finding this sensor on a board or in a smartphone case without a circuit can be difficult even for experienced craftsmen.
In this article, we will analyze the exact physical location of the proximity sensor in the Mi 8T (including modifications with the index M1810F6LG and M1810F6LE), explain the principles of its operation, and give step-by-step instructions for diagnosing and eliminating typical malfunctions.
Physical location of the proximity sensor in Xiaomi Mi 8T
In the Xiaomi Mi 8T, the proximity sensor is integrated into the top display module and is located to the right of the speaker (when you look at the screen with the front side), visually it is impossible to see โ it is hidden under a protective glass and a black masking film. However, when disassembling the device, the sensor is located on a flexible plume that connects the display to the motherboard.
Specific coordinates on the board:
- ๐ Top: 3 mm below the front camera
- ๐ Left/right: 5 mm to the right of the centre
- ๐ Size: 2ร4 mm (together with infrared emitter)
- ๐ Marking: the plume is marked as PROX_SENSOR or APDS-9960 (chip-model)
Importantly, the Mi 8T uses a combined sensor that combines the proximity and illumination sensor (ALS) in a single chip, which means that when one component fails, the entire module often has to be changed.
How the approximation sensor works: the principle of operation
The Mi 8T approach sensor operates on the principle of an infrared barrier:
- The emitter sends an invisible IR signal.
- If an object is near (e.g., an ear during a bell), the signal is reflected and returned to the receiver.
- The microcontroller analyzes the delay time and the strength of the reflected signal, determining the distance.
- At a distance of less than 3-5 cm, the screen automatically turns off.
Features of implementation in Xiaomi Mi 8T:
- ๐ Avago chip is used. APDS-9960 with support for gestures (although in firmware) MIUI this function is off).
- ๐ถ Sensitivity is controlled software-based via the engineering menu (#6484##).
- โก Nutrition: 1.8V, consumption in active mode - up to 200 ฮผA.
- ๐ ๏ธ Calibration is performed automatically at the first turn on and after resetting the settings.
Interesting fact: in some firmware (e.g. MIUI 12.5), the sensor continues to work even when the screen is off, which can lead to false positives in the pocket, due to aggressive optimization of power consumption.
Why does the sensor work in the sun?
How to check the performance of the sensor
The proximity sensor in the Xiaomi Mi 8T can be diagnosed without disassembling the device.
- Visual Test: Open the Phone app and dial ##6484##. Select Proximity Sensor. Close the sensor with your hand - the value should change from 5 (far) to 0 (close).
- Software test: Install the CPU-Z or Sensor Test app from Google Play. Check the sensor's response to the arm approach.
Practical test
- Call another phone.
- Close the Mi 8T to your ear, and the screen should go out in 0.5-1 second.
- Take the phone away, the screen should turn back on.
If the standard calibration does not help:
- ๐ฑ Install Proximity Sensor Reset from Google Play.
- ๐ง Enable the Developer Mode (Settings) โ The phone. โ Version. MIUI, press 7 times).
- ๐ In the developer menu, turn off the option Do not turn off the screen.
After calibration, check the sensor sensitivity in real-world conditions. If the screen goes out too early or with a delay, repeat the procedure or reset the settings to the factory.
๐ก
The calibration of the sensor is reset after updating the MIUI or resetting the settings. After this, be sure to repeat the procedure.
Replacement of the proximity sensor: step-by-step instructions
If the sensor is completely out of order, it can be replaced by itself. Xiaomi Mi 8T will require:
- ๐ง Set of screwdrivers (cross, flat, suction cup for display)
- ๐ฅ Hair dryer or thermo-air station (for softening glue)
- ๐ฆ New display module or separate plume with sensor (article: XIAOMI-1810F6LG-01)
- ๐งด Alcohol for cleaning contacts