Secret codes and login to Xiaomi’s diagnostics service menu

Modern smartphones, especially Xiaomi devices, are complex computing systems that hide many diagnostic tools from the average user. These hidden parts of the system allow engineers in the factory to test components, but are also available to us for deep checks of the condition of the gadget, access to these functions through a special engineering menu that is not displayed in the standard interface.

You can get into this section in several ways, depending on the version of the operating system. MIUI It's either HyperOS or your device's model, and it's mostly a special device. USSD-commands to enter in the Phone app or activation of hidden items through settings. Entering the wrong parameters in the engineering menu can lead to irreversible change in sensor calibration or reset network settings.

In this article, we’ll take a look at all the current methods of accessing system tests, review the purpose of the main sections, and explain how to safely use these tools to test your smartphone.

The main method of activation through the phone application

The most common and safe way to get into hidden diagnostics is to use a standard dial. You need to open the Phone app and enter a special sequence of characters. On most Xiaomi, Redmi and POCO devices, the main code for entering the CIT (Customer Integration Test) menu is as follows:

##64663##

Once the last # character is entered, the screen should automatically switch to the test mode, and you don't need to press the call button. If that doesn't happen, it may be that your model requires the use of an alternate code or activation through settings. In some cases, the system may request confirmation of access rights.

There is also a universal code ##4636## that opens the test menu for device information, which is more secure for beginners, as it basically displays usage statistics and Wi-Fi information, preventing aggressive hardware tests from running. It is useful for checking IMEI, battery status and application usage history.

⚠️ Note: Some codes, such as ##7780##, can trigger a factory reset without further warning. Be extremely careful when entering combinations found online if their source is unknown.

If standard codes do not work, it may be due to restrictions imposed by the operator or firmware of the region. USSD-In the background, requiring a different approach to diagnosis.

Alternative Entry via MIUI Settings

In newer versions of the MIUI 12, 13, 14 shell and the current HyperOS, developers often hide direct codes or change their logic. In such cases, there is a graphical test mode activation interface, which is especially relevant if the dial keyboard ignores entering asterisks and grids in a particular context.

To activate the test menu through the settings, follow these steps. Go to Settings, then select About Phone. Find the MIUI Version (or OS Version) bar and quickly click on it 5-7 times in a row until you notice that you have become a developer. However, for hardware tests, you need a different path.

In some firmware versions, after opening the About Phone section, you need to click on the processor icon or (build number) several times to open the hidden debugging menu. You can also try to follow the Settings path → Advanced Settings → For developers and search for Enable CIT Testing.

If you can't find the right item, try searching for the word "Test" or "CIT" in your settings. The system will tell you what shortcuts are available. This method is less prone to input errors, because it eliminates the human factor when typing characters.

Structure and description of sections of the engineering menu

Once you log in successfully, you'll see a grid with lots of points, each one of which is responsible for verifying a specific component. The interface may vary depending on the model, but the basic functions remain the same. Below is a table decoding the most important tests.

The Touchpanel partition allows you to swipe across the screen and the system will show the trajectory of movement.This is the perfect way to detect "dead zones" or sensor sticking that are not visible in normal use. The Display test consistently paints the screen in different colors, helping to find defective pixels.

Pay special attention to communication-related partitions such as Sim, Receiver (Speaker) and WLAN. They allow you to independently check the operation of communication modules, eliminating program conflicts by the operating system. If you normally lose your network, this test will help you to understand whether it is damage to the antenna.

Detailed check of the display and touch layer

One of the most common reasons for using the service is screen issues. Xiaomi’s engineering menu provides powerful tools for visually evaluating the matrix. Unlike installing third-party apps from the Play Market, the built-in test runs at a low level, bypassing standard interface display drivers.

To run the test, select Display or Screen. The screen will start to change colors: white, red, green, blue, black. Your task is to carefully examine the surface in bright light. White spots (lights) are best visible on a black background, and broken pixels on monochromatic bright fills.

Next is a sensor test, and you're going to be asked to draw lines across all the dotted areas on the screen, and the important thing is that the line should be smooth, without breaks, and if you're in a zone, the line is interrupted or the drawing starts on its own, it's a physical malfunction of the digitizer.

⚠️ Note: Do not leave a static image on the screen OLED-Smartphones in test mode longer 2-3 Prolonged display of a static high-brightness picture can cause pixels to burn out.

If you find defects during the test, it makes sense to take a screenshot (if the feature is available on the menu) or take a screenshot on another camera for proof of malfunction when contacting the warranty center.

Diagnosis of the battery and charging

Power status is a critical parameter for any smartphone. The CIT menu has a Battery or Charger section that displays real-time battery voltage, current and temperature, which is often more accurate than standard desktop widgets show.

If you plug in the charger, you can see if it's charging and at what speed, and it helps you identify faulty cables or power supplies that are formally plugged in but don't transmit the current you need, and you can see the number of recharge cycles, if that information is available for your battery model.

Note the temperature: If the battery temperature exceeds 40°C in idle mode (without running heavy tests), this may indicate a short circuit in the power supply or degradation of the chemical element. Normal heating is observed only during intensive tests of the processor or camera.

Testing of communication modules and wireless interfaces

Wi-Fi, Bluetooth and cellular problems are often software-based, but can also be caused by an antenna module dump. In the engineering menu, you can run a cyclic data transfer for each interface separately. Select WLAN or Bluetooth to start scanning the environment.

For cellular communication, the Sim and Receiver test is important. SIM-The card will show whether the phone sees the installed card, reads IMSI and what signal level (RSSI) Low signal values at full scale in normal mode may indicate a programmatic display error.

It is worth mentioning the test separately. NFC. If you use a smartphone for contactless payment, check this module is mandatory when buying a used device. NFC-device.

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Before checking the communication modules in the engineering menu, turn off all unnecessary Bluetooth devices and forget unnecessary Wi-Fi networks so that the scan results are clean and understandable.

Frequently Asked Questions (FAQ)

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The engineering menu is a powerful self-diagnostic tool, but use it with caution, avoiding sections marked with "Write" or "Calibration" if you are not sure about your actions.