How to replace the proximity sensor on Xiaomi Redmi Note 8T

Smartphone Xiaomi Redmi Note 8T deservedly considered one of the most popular devices of the mid-price segment, but even reliable equipment over time requires attention. One of the frequent problems faced by owners after a year or two of active operation, is the incorrect operation of the proximity sensor. The screen may not go out during a conversation, because of which the user accidentally presses the cheek on the buttons reset or turn on the speaker, or, conversely, the device is constantly locked in his pocket.

Before you bring your device to the service center, consider self-repair, which is often cheaper and faster. Replacing the proximity sensor with the Redmi Note 8T is a moderately complex procedure that requires accuracy and minimal tooling. Most of the time, the problem is not software failure, but physical contamination or mechanical damage to the sensor located under the screen.

In this detailed guide, we will take a look at all the steps of component diagnostics and replacement, focusing on the nuances of working with the display module of this model, you will learn how to properly prepare the workplace, what tools are needed and how to avoid common errors that can lead to damage to the plumes or the screen itself.

Fault diagnosis and sensor inspection

The first step is to make sure that the problem is in the hardware, not the software. Xiaomi smartphones have built-in engineering menu that allows you to test the operation of all sensors without installing third-party software. To start the diagnosis, you need to open the Phone application and enter the universal code # # # # #6484#, after which the CIT menu will open.

In the test list, you need to find the item "Proximity sensor" or "Proximation sensor." When you click on it, you will see the current reading of the sensor. If you hold your palm to the top of the screen (where the speaker is located), the value should change from 5.0 (or far) to 0.0 (or near). If there is no reaction or values "jump" without touching, this is a direct sign of malfunction.

⚠️ Warning: Before any diagnostic procedures begin, make sure to back up important data. Although the tests are safe, accidental system failure during diagnosis is rare, but possible.

Also, avoid software conflicts. Try booting the device in safe mode by pressing the shutdown button and selecting the appropriate item, or simply clear the phone app cache through the settings. If the sensor is working correctly in safe mode, then one of the apps you installed is causing the problem.

Tools and workplace preparation required

Quality repairs are impossible without proper preparation. Redmi Note 8T has a glass back and a fairly tightly assembled body, so opening will require a specific set of tools.Using inappropriate items such as knives or pins can lead to chipped glass or damage to internal components.

To successfully replace the proximity sensor, you will need the following tools:

• 🔧 Set of screwdrivers (including cross-haired) PH000 and PH00) hull-board.
• 🔥 A hair dryer or hot water heater to soften the glue under the back cover.
• 🏦 Medical suction cups or thin plastic shoulder blades (mediators) to open the body.
• 🧲 Magnetic mat for sorting screws of different sizes.
• 🧹 Alcohol isopropyl and lilaless wipes for cleaning contacts.

The workspace should be well lit, as the plumes and connectors in the Redmi Note 8T are miniature, and it is also recommended to use an antistatic bracelet or regularly touch a grounded metal object to avoid damage to electronics by static electricity.

💡

Use a magnetic mat and draw a pattern of screws directly on it with a marker. Rotors of different lengths can damage the board or not get into the holes if you confuse their location.

The process of disassembling the smartphone Redmi Note 8T

Disassembly begins with extraction SIM-So you can get a tray that allows you to release static stress and facilitates access to the insides, and then you need to heat the perimeter of the back cover with a hair dryer to a temperature around the temperature. 80-90 Do not warm one point for too long so as not to damage the battery or OLED-Keep the dryer at a distance. 3-5 See and move it evenly along the edges.

After warming up, gently insert the suction cup at the bottom of the back cover and pull up slightly, creating a gap. Insert a plastic blade into the resulting gap and guide it along the perimeter, cutting the adhesive layer. Act slowly so as not to damage the fingerprint scanner plume that may be glued to the lid.

Once the lid is removed, you'll have access to the bottom of the case, and you'll have to unscrew all the visible screws that are fixing the plastic protective lining, and the number of screws that you can use varies depending on the board's revision, so you'll have to look at the surface carefully, and when you remove the lining, you'll see the battery, the bottom plate, and the main plume.

⚠️ Warning: You can only turn off the plumes after the battery is turned off! First of all, disconnect the battery connector from the motherboard to prevent short circuits.

Then you have to disconnect the antenna module and the lower board plume, carefully slap the connectors with a plastic blade, avoiding the use of metal tools that can damage the contacts, and then you can remove the battery by first unhooking it from the body if you plan to work in close proximity to it, although this is not always necessary to replace the sensor.

Dismantling of the display module and access to the sensor

In the Xiaomi Redmi Note 8T, the proximity sensor is integrated into the display module plume or located on a separate board under the screen, depending on the build version. Accessing it requires partial or complete removal of the screen in most cases, which is the most risky step, since the IPS LCD screens (used in the Note 8T) are sensitive to bending and pressure.

The process of removing the screen involves spinning screws around the perimeter of the frame and heating the glue along the circuit of the display. Be very careful: the screen in this model is glued quite strongly. Use a suction cup and mediators, warming the edges with a hairdryer. Don't try to tamper with the corners where the plumes are located.

After you disconnect the display plume from the motherboard, gently lay the screen on the prepared clean surface with the front side up. On the inside of the module, at the top, you'll see a small green or black board with an optical sensor, and this component is responsible for responding to the approach of objects.

In some revisions, the sensor can be mounted on a flexible plume from the main board and pass under the battery, which requires careful laying of the plume during assembly, so as not to squeeze it. Visually inspect the sensor: if it shows dust, glue or contamination on its surface, sometimes it is enough just to clean it with alcohol.

Replacement of sensor and assembly of device

If cleaning doesn't work, a component is replaced. The new proximity sensor for the Redmi Note 8T usually comes along with a new charging plume or as a separate module on a flexible board. Gently unplug the old sensor by heating the mounting site, and install a new one, making sure the contacts match.

When you build the device, you'll do the reverse. First, connect the display plume to the motherboard, make sure it's up before you click. Then plug the battery in and check the touchscreen and the image without screwing the screws, and that will prevent you from re-disassembling in case of an error.

After successful testing, apply a new layer of glue (B-7000 or special glue pad) to the frame and press the back cover. Lock the device with rubber bands for 15-20 minutes until the glue is completely dry. Remove the excess glue that protrudes at the edges.

Calibration and post-repair inspection

After a physical replacement, software calibration is often required. Go to the ##6484## engineering menu again and select the proximity sensor test. There should be a Calibrate button at the bottom of the screen. Press it and follow the instructions on the screen: usually you need to close the sensor with your hand and then remove it.

Successful calibration is confirmed by the message "Pass" or "Success." If the calibration does not pass, try to repeat the procedure 2-3 times. Sometimes it helps to completely reset (Hard Reset), but this method should only be resorted to if other methods are ineffective, having previously saved data.

⚠️ Warning: If after replacement and calibration, the screen continues to behave strangely (extinguishes at a distance of 10 cm or does not go out at point-blank range), perhaps an unoriginal sensor with a different sensitivity will be installed.

The final check includes a test call. Call your phone from another phone and hold the device to your ear. The screen should go out instantly and light up immediately after you move away. Also check the speaker mode - the sensor should not affect the screen if the speaker is turned off.

💡

Part quality determines 80 percent of repair success, and cheap sensors often have incorrect sensitivity, leading to repeated calls.

Frequently Asked Questions (FAQ)