Location of the microphone on Xiaomi Redmi 4X and solution of sound problems

Owners of Xiaomi Redmi 4X often face situations where the interlocutor stops hearing them or the voice is transmitted with severe distortions. Finding the component responsible for transmitting sound is the first step to solving the problem. Many users mistakenly believe that the microphone module is located next to the speaker at the top of the case, but in this model the design is different.

In fact, the main microphone for talking and recording voice is on the bottom end of the device, and right where the charging connector is, there's a small hole that leads to the sensitive membrane, and understanding the exact location is necessary not only for repair, but also for cleaning the device properly from the dust and pile that often clogs the channel.

Incorrect diagnosis can lead to the fact that you will clean the speaker instead of the microphone, which will not work. In this article, we will discuss in detail how the audio system in Redmi 4X, what hidden holes exist for noise cancellation and how to conduct a diagnosis without complex equipment.

Exact location of main and secondary microphones

The main module that transmits your speech during calls is located on the bottom of the smartphone. If you turn the Xiaomi Redmi 4X screen down, you will see a circular hole next to the Micro-USB connector. This is the input for the main recording element. It is protected by a grid that prevents large dust from entering, but over time can clog.

But there's more than one hole in the design, and there's a small hole in the top end, next to the 3.5mm headphone jack, which is confused by many with the drop hole. SIM-It's actually the input for the second microphone, which is paired with the main one for the noise reduction system.

When you talk, the main module reads your voice, and the top one analyzes background noise, the processor processes data and cuts off foreign sounds, leaving the clean speech of the interlocutor. If you hammer the upper hole, the quality of communication in noisy places can significantly deteriorate.

⚠️ Warning: Do not attempt to clean the holes with sharp metal objects such as needles or pins.You risk piercing the protective membrane or damaging the sensitive element itself, resulting in complete loss of sound.

There is also a third, less obvious channel, where in some board modifications or when disassembling, you can see that the component is integrated into the plume or soldered directly to the motherboard at the bottom of the case, and access to it is possible only after the back cover is removed and the battery is dismantled.

Design features of the Redmi 4X audio system

Xiaomi engineers used a classic audio layout for the budget segment to design the 4X. The main audio input device is a miniature capacitor microphone. It converts acoustic vibrations into an electrical signal. The location at the bottom of the case is due to ergonomics: when talking, the bottom of the phone naturally points to the mouth.

Inside the case, the component is connected to the motherboard either through a flexible plume or through contact pads. In the Redmi 4X, the most common option is when the microphone is part of the bottom plume, where the vibrator and charging connector are also located, which makes it easier to replace: changing the plume as a whole, you simultaneously update the sensitive element.

It's important to note that the sensitivity of the cell depends on the density of the rubber seals. The design of the phone has special rubber cuffs that direct sound strictly into the microphone hole. If these seals were lost or damaged in the previous repair, the sound will be deaf and quiet, even if the component itself is in good working order.

Diagnostics of malfunctions: why you can not hear

Before you take a phone apart, you need to make sure it's hardware, not software failure, that it's the problem. There are several ways to test the audio system, and the easiest way to do that is to record it and listen to it, and if it's silent or it's cracking, it's a physical problem.

The second method is to use the engineering menu, which is a hidden part of the system that is available on Xiaomi smartphones, and to log in to it, you need to open the Phone app and type in a special code, and after you enter the combination, you will open a testing menu where you can check each module separately.

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In the CIT menu that opens, you'll find the item associated with the microphone (usually called "Mic" or "Main Mic"). You'll see a sound indicator on it. You'll tell your phone if the strip moves and changes color, it's coming to the board. If the strip is still, the component is not working.

It's also important to rule out software conflicts. Sometimes third-party applications that have access to a microphone (such as voice recorders, instant messengers or games) can "grab" a device without giving it to the system, and restarting it in safe mode will help identify the culprit.

Cleaning and maintenance of the holes for sound

The most common cause of communication deterioration is banal pollution. Pocket dust, clothing pile and skin fat eventually form a tight plug in the grid. You can use a soft toothbrush to clean. Carefully, without much pressure, walk along the hole with the bristles, sweeping the dust out.

If dry cleaning didn't work, you can use isopropyl alcohol. Importantly, don't pour liquid directly onto your phone! Drink a cotton swab in the alcohol, squeeze it slightly, and treat the mesh carefully. Alcohol evaporates quickly and dissolves fat deposits without causing contact corrosion, unlike water.

To remove the deep-seated dust, you can use a pear to clean the optics or a can of compressed air. Blow at an angle to avoid driving dirt even deeper inside the case. After the procedure, be sure to let the device dry for 10-15 minutes before turning on.

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Use paint tape: stick the piece with a sticky side on the hole and sharply yank. This will help to pull the surface pile without damaging the net.

Regular prevention will help avoid serious problems, and it is recommended to carry out a visual inspection and light cleaning once a month, especially if you carry your phone in your pocket without a cover or in dusty working conditions.

Replacement of microphone: step-by-step instructions

If cleaning didn’t work and the diagnostics in the engineering menu showed no signal, you will need to replace the component. In Xiaomi Redmi 4X microphone is often part of the bottom plume (sub-board flex cable). Change separately only the microphone element makes sense only with soldering equipment and skills of microscopic soldering.

To replace the plume, you'll need a suction cup, a plastic spatula, a cross screwdriver and tweezers. First, you need to turn off the device and remove it. SIM-Then you unscrew the two screws at the bottom of the case, and you remove the back cover (it's held on the latches and glue), and then you unscrew the plastic frame that covers the battery and the plumes.

When the battery is turned off, the main display plume and the bottom plume are disconnected, which goes to the charging socket, and the old plume is carefully removed, and a new one is installed in its place, and the assembly is done in the reverse order, and it is important not to squeeze the plume when you install the frame.

After assembly, be sure to check the sound before you finally stick the lid. If everything works correctly, you can apply a new glue or double-sided tape to fix the back panel.

Software settings and sound improvements

Sometimes the problem is not the hardware, but the MIUI settings. There are noise reduction options in the audio settings section. Try to change their state by turning on or off the "Sound Improvement" or "Sound Adaptation" function, which in some firmware versions are not working properly and drown out the voice.

Also, check the application permissions. Go to Settings → Apps → Permissions → Microphone. Make sure the apps you need (WhatsApp, Telegram, Recorder) are allowed to use the input device. If access is denied, the app will not be able to record sound, creating the illusion of a breakdown.

In rare cases, factory resets are helpful, a radical method that requires all data to be stored beforehand, eliminating software conflicts that may have arisen after a system upgrade or incompatible software installation.

If the problem persists after the plume is reset and replaced, the audio codec on the motherboard may have malfunctioned, a complex case requiring professional repairs at the service center using a soldering station and an oscilloscope.

Frequent mistakes in self-repair

When trying to save money on the service, users often make critical mistakes, one of the most common is the use of aggressive chemicals, acetone or solvents can melt the plastic of the case and damage the insulation of the plumes, which will lead to a short circuit.

Another mistake is ignoring seals. As mentioned earlier, rubber gaskets are critical for acoustics. If you lose them in disassembly, don't build your phone without them. In extreme cases, you can use a thin layer of shrinkage or buy new seals, otherwise the sound will be "empty."

⚠️ Note: When the battery is turned off in Redmi 4X Be careful with the fingerprint scanner plume, which is very thin and easily torn when sloppy with a shoulder blade, and repairing this plume is complicated and expensive.

Also, you should not use a dryer to heat the glue at high temperatures. LCD-screen (spots will appear) or unstick the battery, which is fire-prone. Use only moderate heating (up to the point of the heat). 60-70 degrees) and heat evenly.

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Part quality directly affects the life of repairs. Cheap plumes from markets often fail in a month or two, so it is better to choose components labeled OEM or from trusted suppliers.

Remember that any self-repairing service will give you no warranty if it is still in place. If you are not confident in your abilities, it is better to entrust the work to professionals, especially when it comes to soldering components.