Engineering menu Xiaomi Redmi 4 Pro: access and diagnosis

Gaining access to hidden smartphone system functions is often necessary to conduct a deep diagnostic or health check of individual hardware modules. - Owners of Xiaomi Redmi 4 Pro device (also known as Xiaomi Mi) 4c in some regions) may be faced with the need to check the touch screen, sound calibration or operation of communication modules without installing third-party software. CIT (Customer Integration Test, provides direct access to hardware tests, bypassing standard operating system settings.

Using these tools requires caution, as changing critical parameters can lead to unstable operation of the gadget. However, if your goal is solely to test components, the built-in MIUI tools are completely safe. Below we will discuss in detail all the known ways to activate diagnostic modes that are relevant for current versions of MIUI firmware.

It’s worth noting that the interface may vary slightly depending on the Android version and shell. However, basic navigation principles and code combinations remain the same throughout the Redmi 4 Series lineup. Engineered mode is a powerful tool that turns your smartphone into a professional diagnostic device.

Preparation of the device for diagnosis

Before entering secret combinations, you need to make sure that the device is in good condition. Basic training eliminates false errors that can occur due to software failures or lack of system resources. It is desirable that the battery level is at least 40%, although this is not a critical requirement for testing, unlike the firmware process.

It is recommended to close all background applications so that they do not intercept (focus) input or create a load on the processor during testing. SIM-map, make sure it is correctly defined by the system, as some tests of the communication module may require it. Also check if debugging mode is enabled, although for the basic CIT It's not usually required.

⚠️ Attention: Before any manipulation of hidden settings is initiated, it is strongly recommended to back up important data. CIT safe, random logging into other sections of the engineering menu can lead to resetting.

Make sure the screen is clean and free of severe mechanical damage that can interfere with the touchscreen during calibration. If the display is broken, sensor testing may not be possible or show incorrect results.

Method of entering through standard number dialing

The fastest and most common method of activating the diagnostic interface is the use of USSD-This is the way it works on most versions of the code. MIUI You don't need to get root rights or connect to a computer. You need a regular phone or call app».

Open the dialing app and enter the following character combination: ##6484##. In some cases, the system can automatically recognize the code and go to the menu immediately after entering the last digit without requiring you to press the call button. If the combination is entered correctly, the test list will instantly open on the screen.

• 📱 Enter ##6484## - the main method for starting CIT.
• 📞 Code ##4636## - Opens the menu of phone information and usage statistics.
• 🔧 Code ##64663## – an alternative command for some versions of the firmware Xiaomi.

If nothing happens after entering the code, check if the installed antivirus or spam protection application blocks execution. USSD-Also make sure that the system does not turn off support for entering special characters in the dialing field.

In the rare cases where standard code doesn't work, you can try to type ##3646633##. This code is more commonly associated with MediaTek processors, but it can also be active on some modified Redmi firmware. However, the first option is the priority for the original Redmi 4 Pro based on Snapdragon.

Activation through the About Phone menu

If the code entry does not work, it is possible that the operator or a specific version of the firmware will block the code. USSD-In this case, you can activate the engineering menu through the graphical settings interface. This method requires you to perform a sequence of actions similar to obtaining developer rights.

Go to the Settings section → About the phone. Find the line "Version." MIUI» And press it fast. 7-10 once in a row, usually after 3-4 Clicks will be followed by a “You’ve become a developer” notification, but we need to keep clicking until the new menu opens.

In the list of additional options that opens, you need to find CIT or Kernel Version. Clicking on this item will start the same diagnostic interface as entering the code. If the CIT item is not in the list that appears, look for the “Additional” or “Engineering Menu” tab.

This method is especially useful if the touchscreen is not working properly and you can not quickly type code. Navigating the menu allows you to more smoothly transition to the desired function. After the diagnosis, remember to turn off the developer mode if you no longer need it for debugging applications.

Using ADB for Advanced Users

For professionals and enthusiasts who need access to deeper layers of the system, there is a method of activation via the Android debugging bridge (ADB), which requires a computer installed with an ADB driver and connected via USB cable.

First, you need to activate Developer Mode and enable USB Debugging. Once you connect your smartphone to your PC, open the command line or terminal on your computer. Enter a command to trigger the activity of the engineering menu directly.

adb shell am start -n com.miui.cit/com.miui.cit.CITActivity

This command will force the CIT component to run even if the shortcut is hidden or the codes are blocked. Note that the packet name may vary depending on the MIUI version, but for the Redmi 4 Pro, the combination above is standard. If the system requests debugging confirmation on the phone screen, be sure to agree.

⚠️ Attention: Use ADB Introducing incorrect commands in shell mode can lead to the deletion of system files or a cyclical reboot of the device.

The advantage of ADB is that it can automate tests or log in real time on a computer, and it is an indispensable tool when looking for the causes of unstable hardware modules that do not manifest themselves in normal use.

Overview of the main tests in the CIT menu

Once you log in, you'll see a list of many items, each one of which is responsible for checking a specific component. The interface is usually designed in a minimalist style with large buttons "Pass" and "Fail" (Not Passed).

Among the available tests are the display test (check for broken pixels and uniformity of backlight), the multi-touch test (check response to multiple touches) and the vibration test.

• 🎨 Display – check color rendering and dead zones of the screen.
• 🔊 Speaker & Receiver – test of the sound of the main and spoken speakers.
• 📡 GPS — checking satellite reception and positioning accuracy.
• 🔋 Battery – View detailed cell charge and state statistics.

So you've got to pay special attention to the sensor test, which is that you're going to color the screen in different colors, and you're going to have to swipe your finger across the area, and if the line is interrupted or it's not predictable, it's a problem with the digitizer.

Don’t ignore the GSM/WCDMA/LTE tests, which allow you to check the signal strength and login capability, and if your phone is losing network frequently, this section will help you determine if the problem is in the software or the radio module.

Touch screen diagnostics and calibration

One of the most sought after features of the engineering menu for the Redmi 4 Pro is sensor calibration.If you notice the phone reacting to latency or "ghost" taps, this section can help. TP.

In calibration mode, you may be asked to click on certain points on the screen or draw lines. The system remembers the response of the matrix and adjusts the sensitivity. After the procedure is completed, be sure to save the changes if this option is provided by the current version of the software.

On modern versions of MIUI, the sensor’s software calibration is often blocked by the manufacturer, and the menu is only used to diagnose, not correct, physical defects.

If the test shows multiple touch omissions, the problem is likely hardware in nature, in which case the software methods are powerless and a touchscreen replacement will be required, however, if the problem is caused by static electricity or a temporary controller failure, rebooting after the test can improve the situation.

💡

If the sensor test only shows failures in certain corners of the screen, try to warm up the body carefully (without strong pressure) with a hairdryer in this area - sometimes this restores the contact of the plume, if the cause is the departed glue.

Verification of communication modules and GPS

The communications section contains tools to check antennas and modems, and you can see the current signal strength (RSSI), network type, and base station identifiers, and for the average user, this data may seem complicated, but it's critical for service center engineers.

Test GPS So if you can see if the device can see satellites, run the test and wait a few minutes in a place with good visibility of the sky, if the number of satellites is zero, maybe the antenna connector inside the case has gone off or has failed. GPS-module.

Also available in this section are Wi-Fi and Bluetooth tests, which allow you to check data transfer and connection stability, and if the phone does not turn on Wi-Fi or immediately turns it off, this test will confirm the corresponding chip on the board malfunctions.

💡

Successful completion of all communication tests does not guarantee perfect reception in difficult conditions, but confirms the serviceability of the main power supply chains and antenna control.

Don't forget to check the vibration test. The Redmi 4 Pro uses a separate vibrator, and its failure is often perceived by users as a software bug. If there is vibration in the engineering menu and there is no vibration in the system, the problem should be looked for in the settings of the sound profiles.

Frequently Asked Questions (FAQ)