Buying a smartphone in the secondary market or checking a device after a long downtime is always fraught with risks. Xiaomi Redmi 4X, despite its age, is still in demand due to its reliability and autonomy, making the question of “how to check Xiaomi 4X” relevant for thousands of users.
The process of verification requires a systematic approach, covering both visual inspection and the use of specialized tools. The appearance of the case can tell a lot about the past of the gadget, but the true state of the hardware is often hidden from view. Ignoring detailed diagnostics can lead to the purchase of a device with a “killed” battery or a replaced low-quality display.
In this article, we’ll take a step-by-step approach to make sure your smartphone is healthy. We’ll look at MIUI’s regular tools, secret codes for logging into the engineering menu, and third-party stress test utilities, and following these guidelines will allow you to make an informed decision about buying or repairing.
External inspection and configuration check
You need to start diagnosing it well before the power goes on. Carefully inspect the case for chips, deep scratches and scuffs, especially in corners and around ports. If the seller claims that the phone was used neatly, but you see traces of mechanical impact, this is a reason to doubt his words. Pay special attention to the joints between the frame and the screen: the presence of glue, gaps or backlash may indicate unskilled repair or replacement of the display.
Check the screws at the bottom of the case near the charging socket. On Xiaomi's original devices, they are often sealed or have specific notches. If the screws are torn, scratched or different in color from the factory, the phone has been opened. This is not always bad, but requires additional verification of internal components.
⚠️ Note: If rainbow shimmers or “snow” are visible under the magnifying glass, this is a sign of a poor-quality copy of the display or damage to the matrix, even if the glass is whole.
The kit can also give clues. The original box should have a clear print and matching IMEI-code with a sticker on the back cover (if it is removable) or in the system. Check the charger: the original Xiaomi blocks have a high-quality build and clear labeling, whereas cheap counterparts often heat up and have a backlash of contacts.
Basic diagnostics through CIT engineering menu
The most reliable way to test the functionality of all modules is to use the built-in CIT (Customer Integration Test) menu, which does not require root rights or additional software installation, just open a standard "bell ringer" and enter a special code, this section allows you to test each component separately, from the vibrator motor to the light sensors.
To get into the test menu, dial the combination ##6484## or ##64663#. If the code is entered correctly, the list of tests will open. Here it is important to consistently check the main nodes. For example, the Touchpanel test will make sure that there are no dead zones on the screen, and the Receiver and Speaker test will show the presence of wheezing in the dynamics.
☑️ Checklist of checks CIT
Don’t miss the sensor test, as the Redmi 4X often fails the proximity sensor, which prevents the screen from going out during a conversation, and be sure to check the cameras (front and main) for focus and black spots on the matrix. If some test doesn’t start or shows an error, this is a sure sign of a malfunction of the corresponding module.
Authentication and status of the device
The question of authenticity is especially acute, as there are many replicas on the market. 4X, You can use the official check-in service. IMEI-code that can be found in the phone settings or on the box.
Go to the official Xiaomi authentication site and enter the IMEI in the appropriate box. The system will show the device model, activation date and warranty status. If the site says “Not found” or the model is different from the one claimed (for example, instead of 4X shows Redmi Note), you are a fake or a cross-stitched clone.
| Parameter | Original Xiaomi 4X | Remark/Clone |
|---|---|---|
| Processor | Snapdragon 435 | MediaTek (often old) |
| Screen resolution | 1280x720 (HD) | Often lower or interpolation |
| MIUI Version | Official, updated | Static, not updated |
| Imprint scanner. | It works fast and accurately. | It is not present or works as a button. |
Also worth paying attention to is the firmware version. On the About Phone menu, click on the MIUI version several times to see the details. Original devices have a digital signature. If the version bar is the prefix "CN" (China) and the seller claimed that the phone is global, then the firmware has been manually changed, which can cause notification and language problems.
How to distinguish the Chinese version from the Chinese version?
Detailed analysis of battery status and charging
Since Redmi 4X was released several years ago, battery health is a critical parameter: battery wear directly affects battery life and system stability, and you can check the current capacity and number of charging cycles through the engineering menu or special applications.
In the CIT menu, select Battery. This shows the current charge, voltage and, importantly, status. If the system writes "Bad" or capacity is well below the declared 4100 mAh (for example, less than 3000 mAh on the first turn on after a long downtime), it is time to change the battery. Also pay attention to temperature: sharp heating in idle mode indicates problems with the power controller.
⚠️ Attention: Battery bloating is not just a defect, it's a fire hazard. If the back of the phone is raised or the phone is lying on the table and wobbles when it's spinning, the battery needs to be disposed of urgently.
For a deeper analysis, you can use utilities like AccuBattery or Ampere, which allow you to track the actual current strength during charging and discharging. The normal charging current for this device is about 1.5-2.0 Ampere when you connect to the original unit. If the current jumps or is significantly below normal, check the cable and the Micro-USB connector for oxidation or loosening.
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To extend the life of an old battery, avoid charging in the cold and don’t leave your phone on charge all night if it’s already 100 percent.
Screen and touch screen testing
The display is one of the most expensive components of a smartphone. - Xiaomi Redmi 4X fixed IPS-A matrix that, when used carefully, lasts for a long time but may have defects, and checks begin with a visual inspection with a white background on: look for yellow spots, broken pixels (dots of a different color), or uneven lighting around the edges.
To test the touchscreen, there's a Touchpanel test on the engineering menu, and you're going to be asked to swipe your finger across all the lines of the grid, and if a line doesn't stain or stain itself (ghost touch), it means the digitizer is damaged, and it's a common problem after falls, even if the glass is intact.
Also check multi-touch. Redmi 4X supports up to 10 simultaneous touches. Press multiple dots on the screen at the same time; if the phone "loses" a finger or reacts with a delay, this may indicate problems with the plume or screen controller. In games or when you quickly scrolle the tape, this will manifest as "twitching" the image.
Memory and performance check
Redmi 4X performance is based on the Snapdragon 435 processor. While it's not a flagship solution, it should ensure smooth interfaces. Check the device for "freezes" when switching between applications. If the phone hangs even in the settings menu, it may be a problem with crowded or broken flash memory.
Use benchmarks like AnTuTu Benchmark or Geekbench. This model is normal for an AnTuTu score of 40,000 to 45,000 (version 7 or 8). If the score is much lower, check if background miners or viruses that are loading the processor are running, and low scores can indicate trolling due to dried thermal paste.
Be sure to check the amount of memory available. In version 3/32 GB, the user should have about 22-24 GB of internal memory available. If much less is available (for example, 8 GB), it may be that the flashing was made incorrectly or the memory is physically smaller than the declared one (which is typical for fakes).
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A sharp drop in file writing speed or persistent errors when installing applications is a sure sign of wear and tear on the internal memory of eMMC.
Diagnostics of communication and Wi-Fi/Bluetooth modules
The last but important step is to check the wireless modules, turn on the Wi-Fi and try to connect to the network, the signal should be stable, the speed should be consistent with the tariff, if the phone sees the network but does not connect, or the connection breaks down in the next room, the antenna contact on the board may have burned out.
Bluetooth check is done by trying to transfer the file to another device. The file must be transmitted without errors and breaks. GPS-navigation: run maps and wait for location to be determined. Indoors, the signal can be caught for a long time, but on Redmi Street 4X It should determine the coordinates in 10-20 seconds.
Don't forget to check the work. SIM-Insert the SIM cards of different carriers and make sure the phone sees the network. 4G (LTE). If the phone drops a call or doesn’t see the network in the confident reception area, the problem may be in the antenna module or radio part of the device.