Xiaomi’s Redmi line of smartphones are famous for their functionality, which is often hidden from the eyes of the average user. One of the most powerful tools for diagnosis and fine-tuning is the so-called engineering menu. On the Redmi 8 model, access to these features allows you to conduct a deep hardware check without the need to connect to a computer or install third-party applications.
Many gadget owners are faced with the need to check the performance of the sensor after a fall or to assess the real state of the microphone for communication problems. Standard settings Android does not provide comprehensive information about the hardware. CIT-Menu (Customer Interface Test) that is embedded in the shell MIUI. This is not just a list of parameters, but a full-fledged diagnostic complex.
In this article, we will go through all the ways to log into the hidden part of the system, review the basic tests and answer frequent questions. It is important to understand that interfering with system services requires caution. Incorrectly changing some parameters can lead to malfunctioning of the device. However, if you follow the instructions, the process will be safe and informative.
What is the engineering mode on Redmi 8
Engineering Mode, or CIT, is a set of utilities for testing each module of a smartphone individually. Unlike the usual settings menu, here you can force the vibrator to start, turn on the flash, check the accelerometer or see the real battery charge in millivolts. It is an indispensable tool when buying a used device or looking for the reasons for the strange behavior of the system.
On Xiaomi Redmi 8, this section is hidden from random access so that inexperienced users do not change the critical parameters of the radio module or display calibration.It is accessed through special codes or certain actions in the interface. Code ##6484## is a universal key for all Xiaomi smartphones with a MIUI shell. Use of this code is safe and does not require superuser rights (Root).
The menu functionality covers almost all aspects of the phone: from checking the color reproduction of the screen to testing. GPS-Each test results in a Pass (successfully) or Fail (error) format, which allows you to quickly locate a malfunction, whether it is a software failure or a physical failure of a component.
⚠️ Note: Do not change the values in the radio frequency sections (RF) Or calibration of sensors if you're not a skilled technician, and factory calibration resets can cause communication quality to deteriorate or the touch screen to malfunction.
The main ways to enter the hidden menu
There are several proven methods of activating the diagnostic mode on the Redmi 8. USSD-This method works even on locked firmware versions, since the command is processed at the system level, not the network.
The second way is to navigate through the standard settings menu, which can be useful if the keyboard doesn't respond to character input, or if you want to visually see where you're going, and both of these methods lead to the same result, which is that you start the CIT interface.
- 📞 Entering a combination of characters in the “Phone” application is the fastest way to activate.
- ⚙️ Settings through Settings» → «The phone» → «The kernel version is an alternative path.
- 🔍 Using the search bar in the settings to find the item "Kernel Version».
It's worth noting that some global firmware versions may not display code input on the dial screen, but the menu will still open. If the code doesn't work, try reprinting it carefully, without unnecessary pauses. The system responds to the input sequence instantly.
Step-by-step instructions by code and through settings
To enter through dialing, open the standard Phone app you usually use for calls. Enter the sequence of characters: ##6484##. Once you enter the last character (grid), the menu should open automatically. You do not need to press the call button, in fact, it can interrupt the process.
If you prefer a GUI, go to Settings. Scroll down the list and select About Phone. Find Kernel version. Some versions of MIUI require you to press that line 5-7 times in a row to activate the hidden transition. Other times, just one tap if the code has already been entered.
☑️ Checklist before entering CIT
Once you log in, you'll see a list of tests with the names of the components in English, navigation is done with a simple touch, use the Back button on the screen or the physical navigation button to go back, and the top of the screen usually displays the device model and the firmware version, which is useful for data reconciliation.
Overview of the main tests and diagnostic functions
The list of available checks on Redmi 8 is quite extensive, each position is responsible for a specific node. For example, the TouchPanel allows you to check the sensor response across the entire screen area by drawing lines, which helps to identify "dead zones" that are not visible in normal use.
The Speaker and Receiver section checks the main speaker and the conversation speaker respectively. The system plays test audio files, and you need to confirm if you hear sound. This is critical for diagnosing sound problems when you call or watch videos.
| Name of the test | Function | The result |
|---|---|---|
| TouchPanel | Touchscreen check | Drawing lines |
| Color | Matrix verification | Change of colours |
| Vibrator | vibrator test | Vibration. |
| GPS | Search for satellites | Coordinators |
A GPS test is also available, which shows the number of satellites visible and the accuracy of the positioning, and if the navigation is slow, this test will help you see if the module sees satellites at all, and the WLAN and Bluetooth check the operation of the wireless modules in echo test or scan.
Hidden camera tests
Sensor check and display calibration
One of the most important features for Redmi 8 users is checking the accelerometer and gyroscope. The Accelerometer allows you to calibrate the position sensor. If the autorotation of the screen is not working correctly or the navigation in the cards is "glutching", resetting the calibration in this section can solve the problem.
To calibrate, you put your phone on a flat horizontal surface and press the calibration button, the system reads the data and sets zero values, then you recommend restarting the device, a simple but effective procedure that is often ignored by owners.
A Color display displays monochrome images (white, red, green, blue, black) that reveal broken pixels, lights, or uneven backlights, and white backgrounds show matrix defects that can be invisible when bright.
⚠️ Warning: When checking the screen for white, reduce brightness to a minimum if you have sensitive eyes.
Diagnostics of sound, microphone and communication
Sound problems are a common reason to go to the service. In the engineering menu, you can separately check the main microphone, noise cancellation and conversational speaker. The Microphone test records your voice and immediately plays it back. If you hear yourself clearly, then the microphone is good, and the problem may be in the application or network.
The SIM and Network section shows the technical connectivity parameters: signal strength in dBm, network type (LTE, 3G), base station ID. This is useful information for those living in an unsustained reception zone. A signal value closer to 0 is better, for example, -80 dBm is better than -110 dBm.
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If you hear a strong crackling or hissing on the microphone test, try gently cleaning the microphone hole with a soft brush. Often the problem lies in the banal dust.
Work is also being checked FM-radio (if supported by a region) and headphones, and when you connect the headset, the system must automatically determine if it is present, and if the headphone test says "Not detected", it may be that the 3.5mm connector is contaminated or damaged.
Frequent Problems and Solving Them Through CIT
Often, users are faced with a situation where the proximity sensor stops working (the screen does not go out during a conversation). The CIT menu has a Proximity test. Close the top of the screen with your hand. If the value changes from 5.0 to 0.0 (or vice versa), the sensor is intact. If the numbers do not change, you may need to calibrate or replace the sensor.
Another common problem is fast discharge, and in the Battery section, you can see not only the percentage of charge, but also the voltage and the temperature, and sudden surges in voltage or too high a temperature in idle can indicate wear and tear of the battery.
- 🔋 Checking the real battery voltage to assess wear.
- 📡 Signal Level Test for Diagnosing Communication Problems.
- 🔊 Separate test of speakers to detect wheezing.
If the test shows Fail, try restarting your phone and taking the test again. Single software failures can give false positives. If the error repeats, this is a good argument for contacting the warranty service.
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The engineering menu is the first step in the diagnosis, and if the tests show Fail, the software reset will not help, you need to replace the hardware component.