Xiaomi’s Redmi series is well-deservedly popular for its excellent value for money, but even reliable devices can run into hardware problems over time. One of the most common complaints of Redmi Note 7 owners is that voice quality is deteriorating or sound disappears completely during a conversation. Understanding where the microphone is in this model is the first and critical step to self-diagnosing a malfunction or conducting a careful repair.
In this article, we will take a closer look at the design of the device so that you can accurately determine the location of the main and secondary microphones. Knowing the exact layout of the components will help you avoid accidental damage to the plumes when you try to clean the dynamic grid or replace a part. We will look not only at the physical coordinates of the modules inside the housing, but also at software aspects that can affect the operation of the sound recording system.
Remember that any interference with the design of a smartphone requires caution and appropriate tools. If you plan to disassemble the device, make sure you have experience with small electronics. Wrong actions can damage other components, such as the battery or the display plumes, so it is important to act strictly according to the instructions.
Design features of the audio system Redmi Note 7
The engineering layout of the Xiaomi Redmi Note 7 (codenamed lavender) uses two microphones to provide noise reduction and recording stereo sound in video. The core module responsible for transmitting your voice to the interlocutor during a phone conversation is integrated into the bottom of the board, but its hole for collecting sound is displayed on the bottom end of the case. This is the standard solution for most modern smartphones, allowing you to minimize the distance to the user’s mouth.
The second, the auxiliary microphone, is located at the top of the device, usually next to the headphone jack or in the main camera unit, and its main task is to analyze background noise and transmit data to the processor for algorithmic sound cleaning, as well as record audio when shooting video in horizontal mode. Any of these elements can cause the interlocutor to hear you poorly, distorted or not hear at all.
Importantly, the Redmi Note 7 uses a 3.5mm combined connector that also serves as an antenna. The proximity of the audio modules to this connector requires special care when repairing. Any careless movement of a screwdriver in the upper part of the case can damage not only the microphone, but also the power chain or antenna contacts.
⚠️ Warning: Before any disassembly of the smartphone, be sure to completely turn off the device. Attempting to turn off the microphone plumes or other components under voltage can lead to a short circuit on the board and irreversible failure of the power controller.
To visually look for microphone holes, look at the ends of the device. The bottom hole is usually symmetrical to the dynamics, but is often shifted closer to the center or edge depending on the revision of the case. The top hole is a tiny hole with a diameter of less than 1 mm, which is easily confused with a process hole or sensor.
Exact location of microphones
To pinpoint where the microphone is in Xiaomi Redmi Note 7, you need to understand the difference between the outer holes and the inner location of the modules. The outer hole of the main microphone is on the lower end, often covered with a fine metal or plastic mesh, and in some revisions it can be hidden under a decorative element next to the Type-C charging port.
The internal core microphone is mounted on a subboard that connects to the motherboard with a plume, and the second microphone is mounted directly on the motherboard at the top, or on a separate plume from the headphone jack, and when you disassemble the phone, you'll see them as small black or silver cylindrical or rectangular perforated elements.
Interior connection diagram
Below is a table that systematizes the arrangement of components for rapid orientation:
| Type of microphone | Outer location | Inland location | Function |
|---|---|---|---|
| Primary (Primary) | Lower end, next to the charging port | Lower fee (Sub-board) | Conversations, dictaphone (main mode) |
| Additional (Secondary) | Upper end, 3.5 mm connector | Motherboard (top) | Noise suppression, video recording |
| Dynamic (Ear-piece) | Top of the screen (auditory) | Under the screen/in the display module | The interviewer (not to be confused with the microphone!) |
The hearing speaker in the Redmi Note 7 is hidden under the top of the display and has no pronounced hole on the frame, while the microphone always has direct access to air through a calibrated hole. An identification error can lead to an attempt to "clean" the speaker, which will not solve the problem with voice transmission.
Diagnostics of malfunctions before disassembly
Before you start physically disassembling and finding where the microphone is in the Xiaomi Redmi Note 7, you need to eliminate software failures. Often the problem is not in the hardware, but in the conflict of applications or system settings. The first step should be to check the device is in safe mode or using the engineering menu.
You can use a special code to access the equipment testing in the MIUI shell. Open the Phone app and type the combination ##6484##. This will open the CIT engineering menu where you can test components. Select the item associated with the microphone (usually "Main Mic" and "Sub Mic"), and say a few words while watching the signal level change on the screen.
If the signal level does not change in the engineering menu or shows minimal values during a loud conversation, this indicates a hardware malfunction. However, if the graph responds normally, the problem may be in the operator's network, the settings of a particular application (for example, WhatsApp or Viber), or the presence of a protective film that covers the hole.
⚠️ Warning: Do not use sharp metal objects (needles, pins) to clean the microphone holes. You risk piercing the microphone membrane or damaging the moisture mesh, which will permanently disable the part and deprive you of warranties.
Module replacement and cleaning process
If the diagnostics confirmed a hardware problem, you will need to disassemble the device. To access the bottom microphone in the Redmi Note 7, you need to remove the rear glass cover. It is glued to a special glue, so you need to preheat the device on a heat pad or hair dryer around the perimeter to a temperature of about 80-90 degrees Celsius.
Once the lid is removed, unscrew the screws that hold the plastic frame and gently unplug the plume from the bottom board to the motherboard. The main microphone is on this lower board. To replace it, you'll need to unsold the old module and solder the new one using a thin stinging iron and flux, or replace the entire lower board assembly, which is easier for beginners.
☑️ Checklist before replacing microphone
Replacing the top microphone requires deeper disassembly, including removing the motherboard. In this case, it is important to remember the order of spinning screws, as they can be of different lengths. When installing a new module, make sure that the rubber seal (if designed) fits tightly to the body, ensuring tightness and the correct direction of sound.
Software settings and reset
Sometimes, even after a microphone is replaced or when it is serviceable, the sound may remain quiet due to software constraints. MIUI has settings that regulate volume and noise cancellation. Check Settings → Sound and vibration → Additional audio settings. Make sure the Noise Cancel option is activated but does not work in conflict with the headset.
It's also worth checking for app permissions. If the microphone doesn't work in just one app (like Skype), go to Settings → Apps → Application Management, find what you want and check the "Permissions" section. Access to the microphone should be enabled. In some cases, resetting all settings to factory settings helps, but this is a last resort.
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Useful tip: Before resetting or changing the microphone, back up important data. Sometimes, after replacing the audio components, the system may require calibration that takes place automatically when you first turn on, but it is better to have a clean system.
Don't forget to check the system updates. Xiaomi periodically releases patches that fix the error of the audio drivers. Go to Settings → About Phone → MIUI version and click "Check Updates." Installing the current firmware can solve the problem without physical intervention.
Frequent mistakes in self-repair
Self-repairing the Redmi Note 7 comes with risks, especially given the glass back cover and the complex layout, and one of the most common mistakes is damage to the main camera plume or fingerprint scanner when you remove the frame, which are located in close proximity to the work area.
Another mistake is using the wrong adhesive to build. Acrylic glue or superglue can evaporate and settle on the lenses of cameras or microphone membranes, making them less efficient. Use only specialized adhesive B-7000 or T-7000, which remains elastic after drying.
⚠️ Warning: Do not drag the screws of the board mounting during assembly. Excessive force can lead to cracks in the board texture or breakage of plastic racks, which will make further repairs impossible without replacing the body.
Also, users often forget to connect antenna contacts after assembly. If you see golden spring contacts on the board, make sure they are tightly pressed by the back of the case or board. Poor antenna contact can lead not only to a bad network signal, but also to increased noise in conversation.
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The sound quality depends on the tightness of the microphone channel, and if the rubber gasket is crooked or missing, the sound will be quiet and deaf even with the new microphone.
Prevention and care of the audio system
To avoid a repeat of a faulty microphone situation, it is recommended that you regularly clean the device prophylactically.The dust and pile that accumulates in the holes are compressed over time and block the sound.Use a soft brush or pear to blow out dust, but do not blow with your mouth to avoid moisture.
Using high-sided protective covers can protect the bottom of the phone from direct hits and dirt. However, make sure that the case itself does not overlap the technological holes. Some cheap cases have inaccurate perforations that shift over time and block air from accessing the microphone.
The Redmi Note 7's waterproofing has limited resource. Moisture trapped inside can oxidize microphone contacts even some time after the event. If the phone is wet, turn it off immediately and dry it in a warm, dry place, avoiding using a hair dryer at high temperatures that can damage the screen's adhesive connections.
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Regular visual inspection of microphone holes helps detect contamination at an early stage, when the problem can be solved by simple cleaning without resorting to disassembly.
Conclusion and recommendations
Understanding where the microphone is in Xiaomi Redmi Note 7 and knowing how it works allows you to effectively solve sound problems, whether it's a software failure that requires resetting or a hardware breakdown, necessitating a module replacement, a competent approach will save you time and money, the main thing is to act consistently and not ignore simple diagnostic methods.
If you are not confident in your abilities or do not have the necessary tool for soldering chips, it is better to contact a specialized service center. Professional repair ensures the use of original spare parts and maintain the tightness of the case, which is especially important for longevity devices.