Problems with the sound recording or quality of voice calls on Xiaomi and Redmi smartphones often take users by surprise. Device owners may face a situation when the interlocutor does not hear them, the voice sounds quiet, or the recording of the recorder is interrupted. Before carrying the gadget to the service center, you need to conduct self-diagnosis to exclude software failures.
In this article, we will take a look at all the available methods for checking the main and secondary microphones, learn how to use built-in system tools, special engineering codes and third-party utilities to accurately determine the fault, and get the right diagnosis to help you understand whether a replacement hardware component or software adjustment is required.
It's worth noting that today's Mi and Poco smartphones are equipped with a sophisticated noise reduction system that uses multiple microphones, and if one of them fails, it can critically affect the quality of communication as a whole, so it's important to check each element of the audio system separately to localize the problem.
Use of built-in voice recorder for initial check
The easiest and most affordable way to quickly assess audio input performance is the standard Dictaphone app, which is pre-installed on all devices with a MIUI or HyperOS shell and does not require additional software, which allows you to record and listen to the sound, assessing the presence of noise, cracking or no signal at all.
To do the test, open the app and press the record button. Speak to the phone, periodically covering the lower part of the case, where the main microphone is located, and then the upper part, where the additional one is located, to help you understand which channel is working correctly and which one is failing.
⚠️ Warning: When testing, make sure the room is quiet, and extraneous sounds can distort perceptions of recording quality and lead to false conclusions about a microphone malfunction.
After recording, be sure to listen to the file in your headphones. Pay attention to static interference, which may indicate physical damage to the membrane or oxidation of contacts inside the device. If the sound is clear and loud, the problem is likely to lie in the settings of a particular application, such as a messenger.
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Before recording, wipe the microphone holes with a soft dry cloth. The accumulation of dust or pile from your pocket often causes a quiet sound, rather than a breakdown of the electronics.
Diagnostics through CIT Engineering Menu
The most accurate tool for checking hardware components of a smartphone is the CIT (Customer Information Test) engineering menu, which allows you to test each device module separately, including the main, secondary and headset microphones, giving a Pass or Fail result.
To get into the testing menu, open the Phone app and dial the combination ##6484##. If the code doesn't work, you can go through the settings menu: select About Phone, then quickly click 5-7 times on Version of the Kernel or Version of MIUI until the hidden menu opens.
In the test list, find the Main Mic (main microphone) or Sub Mic (additional). Click on it and follow the instructions on the screen. Usually, the system will ask you to say a phrase or just make a sound, after which it will automatically determine the level of the incoming signal.
- 📱 Main Mic – checks the main microphone located at the bottom of the case, which is used for conversations in normal mode.
- 📹 Sub Mic – Tests the top microphone responsible for noise reduction and video recording.
- 🎧 Headset Mic – microphone diagnosis in a connected wired headset or adapter.
If the test shows a Fail result, it is almost guaranteed to indicate a physical malfunction of the component or its plume. In the case of success (Pass) but problems in real life, the cause may be a software conflict or privacy settings.
☑️ Checking in CIT
Checking through the MMI Engineer Menu
An alternative way to make a deep diagnosis is a menu. MMI, It also has a range of features that are available on many Xiaomi models, and it provides extended access to testing of communication and sound modules, and it's accessed through the same dialing interface, but using a different interface. USSD-code.
Type #3646633## into the call app. You'll see Engineer Mode interface. Go to the Hardware Testing tab, then select Audio and Audio Debug, and you can not only check the microphone, but you can force it to change its sensitivity.
In the Microphone Test section, you'll see a list of available microphones. Choose the one you want and press Start. Speak to the device -- the signal strength indicator should respond to your voice. If the bar stays at zero, the microphone doesn't transmit the signal.
⚠️ Attention: On the menu MMI Be careful with changing Gain settings. Too high can lead to overloading of the input and the appearance of strong wheezing or even damage to the speaker when playing.
This technique is particularly useful when standard CIT fails to start or produces erroneous results, and allows you to see the raw signal from the microphone before processing by software filters to reduce noise, which gives a more objective picture of the state of the hardware.
What if the code doesn't work?
Comparative table of diagnostic methods
To make the test method easier to choose, we have systematized the basic methods in a table, each with its own advantages depending on the situation, whether it is a quick check before buying a used device or a deep breakdown analysis.
| Method | Difficulty | precision | Necessary rights |
|---|---|---|---|
| Dictaphone | Low. | Medium | No. |
| CIT's Engineering Menu | Medium | Tall. | No. |
| Apps from Play Market | Low. | Medium | Access to the microphone |
| Menu MMI (Engineer Mode) | Tall. | Maximum | No. |
As you can see from the table, for the average user, the most optimal option is a bunch of voice recorders and CIT menus. They do not require special knowledge and provide enough information for the initial verdict. MMI menu is better used by advanced users who understand the risks of changing system parameters.
Third-party applications for detailed analysis
If the built-in MIUI doesn’t give the full picture, specialized applications from the Google Play store come to the rescue. Programs like Phone Doctor Plus or Mic Test allow you to conduct a comprehensive audit of the audio system with visualization of frequencies and volumes.
These utilities often have more flexible recording settings and can display the signal level in real time as a graph, which helps to notice short-term sound dips or periodic interference that is difficult to hear in a normal listening recording.
But you have to remember access rights, because when you install third-party software, you allow it to access your records and microphone, and only use high-rated, trusted apps to keep your personal information from leaking.
In addition, some applications allow you to record sound from both microphones simultaneously, creating a stereo track, a unique way to check the synchrony of both channels and the operation of the noise reduction system.
Typical problems and software solutions
Often the problem is not hardware, but software conflicts, for example, after an Android or MIUI update, application permissions may be lost, and if WhatsApp or Telegram do not have access to the microphone, you will not be able to send voice messages, although the recorder will work properly.
You can check and change these settings in Settings → Applications → All Apps. Select a problem application, go to Application Permissions and make sure the Microphone switch is activated. It is also worth trying to clear the app cache.
Another common reason is the active Do Not Disturb mode or third-party equalizers enabled, which can block the input signal. Try restarting the device in Safe Mode to eliminate the influence of third-party software.
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If the microphone does not work in only one application (for example, Skype), and the voice recorder and calls function normally, the problem is in the settings of access rights or the application itself, and not in the smartphone.
When repairs or replacements are needed
If none of the software methods worked and the engineering menu gives an error, it is likely that physical intervention is required. Replacing the microphone is not a complicated procedure, but requires care, since often this component is soldered into the charging port plume or goes into the module with buttons.
The signs of physical breakdown are: complete absence of recording, constant strong cracking that does not change with the movements of the phone, or moisture entering the body. In the latter case, you can not delay - the oxidation of contacts occurs very quickly.
Self-replacement is possible if you have soldering skills and the appropriate tool, but to maintain the warranty and sealability of the case (if it is claimed), it is better to contact an authorized Xiaomi service center.