The problem of the Xiaomi Redmi Note 8 Pro screen not going out during a conversation is one of the most common and annoying for owners of this popular model. The user may find that the cheek or ear interrupts the conversation by pressing the reset or volume buttons, which makes normal communication impossible. This phenomenon is often associated with software failures in the MIUI shell, but in some cases the cause is physical damage or contamination of the sensor. In this article, we will discuss in detail all methods of diagnosis, software calibration and hardware troubleshooting.
Before you start to make complex manipulations, you need to understand how this module works. The Redmi Note 8 Pro uses an optical sensor that emits infrared light and reads its reflection from nearby objects. If the system sees a reflection, it thinks that the phone is near the ear, and it turns off the display. A calibration failure causes the device to either constantly "see" the object (the screen is black always) or not see it at all, which is why primary diagnosis should begin with checking the software settings, not immediately going to the service center.
Importantly, ignoring the problem can lead to random actions on the screen, including dialing unnecessary numbers or sending messages. In 80% of cases, the problem is solved by software calibration through the engineering menu without opening the case. However, if the software methods do not help, there is a high probability of failure of the plume or the touch module itself, which will require deeper intervention. Let's go through all the stages of restoring your gadget consistently.
Primary Diagnostics and Eng Menu Checkup
The first step is to determine whether the malfunction is software or hardware. To do this, the Xiaomi MIUI shell has a built-in engineering verification tool. You need to open the standard Phone application and enter the combination ##6484## in the dialing field. Once the last digit is entered, the system will automatically redirect you to the CIT (Customer Information Test) menu. If the menu does not open, you may be blocked from entering special commands, and you will need to use third-party applications to emulate the set.
In the test list that opens, you need to find a item associated with the Proximity Sensor, and if you click on it, you'll see a screen with numerical values and possibly color indicators, hold your palm to the top of the screen (in the area of the speaker) and remove it. If the values change and the color of the indicator switches (for example, from red to green or from Far to Near), then the sensor is physically healthy and responds to changes in the environment, in which case the problem lies solely in the software.
If the engineering menu values are still in place or the test immediately shows an error, the situation is more serious. This can mean that the sensor plume has moved away from the motherboard, is interrupted or oxidized after moisture enters. It is also possible that the optical element itself will fail. In such cases, software calibration may not give a long-term result and physical intervention will be required. However, even with such symptoms, an attempt to reset or reflash the device can sometimes “revitalize”.
What if the #6484## code doesn’t work?
Software calibration of the sensor
If the CIT test shows that the sensor is responding to the hand but is not acting correctly in real calls, a forced calibration is required. This process forces the Redmi Note 8 Pro system to rewrite the reference light values. To perform this procedure, log back into the engineering menu using the code # #6484## and select the Proximity Sensor test. The "Calibration" button or similar will appear on the screen.
Press the calibration button and follow the instructions on the screen. Usually, the system will ask you to remove all objects from the top of the phone, and then, on the contrary, close the sensor with your palm. It is important to ensure good lighting in the room and no bright light sources pointing directly to the lens, as this can knock down the sensitivity settings. Once the procedure is completed, the phone can automatically reboot.
☑️ Algorithm of correct calibration
There is also an alternative method of calibrating through the engineer's hidden menu if the standard test doesn't work. CIT-You can find the "Version" option, or you can click on the firmware version several times to open the extended menu, and you can find the Prox. Calib setting and reset to factory values, and then you can restart the device and do a real call test again.
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Use a matte protective film instead of glass. Cheap protective glass often has a black frame that covers part of the optical sensor, causing false positives. Matt film has no such frame and better scatters light.
Sensitivity setting in the system
Some versions of the MIUI firmware for the Redmi Note 8 Pro have a separate proximity sensor sensitivity setting, which is in the call settings menu. To get there, open the Phone app, click three dots in the corner or the menu button, and select Settings. Then go to Incoming Calls and find the Approximation Sensor.
You can see a switch or a slider here, if you have "High sensitivity," try turning it off or turning it into standard mode. Sometimes the system misinterprets even a slight movement of air or a change in angle of inclination as an object approach. Standard settings are usually the most stable has been tested for most scenarios.
You should also pay attention to the "Pocket Mode" feature, which, if activated, can turn off the screen when placed in a bag or pocket, but sometimes this feature conflicts with the main sensor. Try temporarily disabling this option in the lock settings or in the "Block" menu, which will help to eliminate the software conflict between the various services of the system that monitor the position of the device in space.
| Parameter | Default value | Recommended value for failures | Impact on work |
|---|---|---|---|
| Sensitivity | Standard. | Reduced. | Reduces the number of false quenchings |
| Pocket mode. | Included. | Off. | Avoids conflicts with the main sensor |
| Automatic. | Off. | Off. | Prevents accidental actions |
| Vibration on touch | Included. | As you wish. | Helps to understand the screen reaction |
Effects of accessories and pollution
One of the most common but often overlooked reasons for the proximity sensor to malfunction is the protective glass or film. Many users, when buying the Xiaomi Redmi Note 8 Pro, immediately glue the protective glass with a black bezel. Accessories manufacturers often make this bezel too wide, and it physically covers part of the sensor’s working surface located in a narrow notch above the display.
And then over time, the surface of the glass accumulates fatty film, dust and dirt that can dissipate the infrared radiation of the sensor. Even a thin layer of fat from the fingers can change the refractive index of light, which will cause the phone to think that it is constantly in the ear. Regular cleaning of the top of the screen with an alcohol napkin or a special spray for optics can instantly solve the problem.
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Remove the protective glass during the diagnostic, and if the sensor worked correctly after removing it, the problem was the accessory, and it needs to be replaced with a better or thinner one.
It's also worth checking the case. Some thick silicone or leather cases with high sides can mechanically press on the sensor area or create a shadow that the system perceives as an object. Try removing the case and checking the phone's performance in a "hungry" form. If the problem is gone, then the accessory is wrongly selected and needs to be replaced.
Resetting and software update
If neither calibration nor cleaning helped, there may have been software errors in the system that affect the sensor drivers, in which case the effective method is to reset the settings to factory settings. Before this procedure, be sure to back up all important data, as all photos, contacts and applications will be deleted in the process. You can do this through the Settings menu -> About Phone -> Resetting.
Also worth checking for operating system updates. Xiaomi periodically releases patches that fix hardware bugs. Go to Settings -> About Phone and click on the MIUI version. If an update is available, install it. Sometimes even re-installing the current firmware version through the Recovery Mode menu helps, allowing you to overwrite system files without losing data (when selecting the appropriate item).
⚠️ Warning: Before performing a full reset (Wipe Data), make sure that the battery is at least 50%. Interrupting the reset process due to battery discharge may cause the system to not be booted and require flashing through the computer.
In rare cases, the problem can be caused by a conflict of a third-party application that has access to the phone's sensors (such as voice recorders, call recorders or launchers). Try loading the phone into Safe Mode. To do this, press and hold the off button, and then press the "Stop" option on the screen for a long time until the prompt to go to Safe Mode appears. If this mode the sensor is working properly, delete the newly installed applications.
Hardware repair and replacement of the module
When all software methods are exhausted, and in the engineering menu, the sensor does not respond or shows critical errors, it is a hardware problem. In the Redmi Note 8 Pro, the proximity sensor is often integrated into the speaker plume or is a separate module connected to the board. Over time, the plume connector may have moved away from frequent falls or vibrations. A careful reconnection of the plume sometimes brings the device back to life.
If reconnection doesn't work, it will require replacing the sensor module itself or the entire plume assembled with the speaker, which requires the ability to disassemble the smartphone, since the back cover of the device is glued and requires careful heating and opening. Replacing the component in the service center usually takes a short time and is not overly expensive compared to replacing the display.
Can I use my phone without a proximity sensor?
When replacing yourself, it is important to use original parts or quality analogues. Cheap Chinese copies of sensors often have the wrong sensitivity or do not work at all with the Xiaomi power controller. After replacing, be sure to conduct the calibration procedure described above, as the new sensor will have different physical characteristics.
⚠️ Warning: Self-disassembly of the smartphone voids warranty. If your device is still in warranty service, do not open it, and contact an authorized service center Xiaomi for free repair.