How to Clean the Microphone in Xiaomi Phone: From Settings to soldering

Reduced voice quality is one of the most annoying problems faced by Xiaomi smartphone owners.Interviewers complain of a quiet sound, echo or no sound during calls, which makes normal communication impossible. Often users mistakenly believe that the problem lies in poor cellular signal or poor performance of messengers, although the root of the evil can be banal hidden in the contamination of the device itself.

In the process of operation, dust, pocket pile, skin fat and even microscopic dirt inevitably enter the microphone holes. Over time, this mass compacts and blocks the access of the sound wave to the sensitive element. Before carrying the gadget to the service center or buying a new one, you should try to fix the malfunction yourself using proven cleaning methods.

In this article, we will discuss in detail how to correctly determine the microphone localization on your Redmi or POCO model, which tools are safe to use and which can cause irreparable harm, you will learn about software methods to improve sound transmission and understand when cleaning will no longer help and you will need to replace the component.

Diagnostics and search for microphone on the body

The first step before any manipulations is to precisely locate the microphones. Xiaomi’s current flagships and budgeters often feature two, three, or even four microphones to implement noise reduction and stereo recording. The primary conversation microphone is usually located at the bottom of the case, next to the charging connector.

The additional noise-cancelling microphones can be on the top end or on the back of the camera box, and to know exactly which microphone is not working, you need to do a simple test, turn on the recorder and alternately talk into different holes, covering the rest with your finger to determine the source of the problem.

Visual inspection in bright light often helps to identify visible contamination, if you see a compressed pile or a dark plug in the grid, then cleaning is necessary, but if everything is clear on the outside, but the sound is gone, the problem can be deeper or programmatic.

• 🔍 Lower end: the main hole, most often hidden behind a decorative grille speaker.
• 📹 Upper end: small round port, often used by a second microphone.
• 🔙 Back panel: The microphone can be hidden next to the flash or brand logo.

⚠️ Warning: Never use sharp metal objects such as needles or pins to pick through the microphone grid.You can pierce the membrane, and then the recovery will cost significantly more than a simple cleaning.

Programmatic verification and calibration

Before we go to physical impact, we should rule out software failures. MIUI and HyperOS have powerful diagnostic tools in their shell. Often users are unaware that a quiet sound can be the result of a software driver error or a malfunction in the Phone application.

To check, use an engineering menu or a standard hardware test. Enter the dialer code ##6484## to get into the CIT menu. Here you can run a "Mic" test, which will record your voice and play it, evaluating the sound quality of each microphone separately.

If the test shows that the microphone is working but the sound is quiet in real life, try resetting the phone app. Go to Settings → Apps → All Apps → Phone → Memory → Clear. This action will not delete your contacts, but will return the call settings to factory values.

You also need to look at third-party applications that can intercept access to the microphone. The access control will show you which programs are using audio input right now. Sometimes background recording in a heavy application can block the normal operation of the main communication module.

Preparation of tools for safe cleaning

Good cleaning requires the right tools, and using improvised tools like cotton swabs often leaves the villi inside the net, making things worse, and you'll need specialized or carefully selected tools that don't damage the delicate components.

The main tool will be a soft brush with natural pile, for example, for makeup or drawing, which allows you to sweep the dust without pushing it deeper, and you will need a high-purification isopropyl alcohol (at least 90%), which quickly evaporates and leaves no conductive traces.

To remove sticky contaminants, blue gel or special adhesive tape is ideal. The use of ordinary water is strictly prohibited, as it causes oxidation of contacts and corrosion, which will lead to irreversible failure of the microphone.

• 🖌️ Soft brush: to remove dry dust from the surface of the mesh.
• 💧 Isopropyl alcohol: for dissolving fatty deposits.
• 🌬️ Pear or canister: for blowing out garbage with compressed air.

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Instead of an expensive compressed air can, you can use a medical pear, which creates enough pressure to knock out the dust, but does not contain chemicals that can damage the plastic.

Mechanical cleaning of the external hole

The cleaning process should begin with removing visible contaminants. Carefully walk with a dry soft brush along the microphone hole, sweeping dust outwards. Movements should be confident but light so as not to damage the protective net, which in low-end Redmi models can be quite brittle.

If dry cleaning doesn't work, go to wet. Wet the cotton swab in isopropyl alcohol and squeeze it carefully so it doesn't drip. Carefully, without much pressure, wipe the area around the microphone. Alcohol will dissolve the fat film, which often serves as a "glue" for dust.

After treatment with alcohol, allow the device to dry for 5-10 minutes. Don't try to speed up the process with a hairdryer, as hot air can melt the adhesive holding the speaker or damage the moisture membranes. It's better to leave the phone lying in the air.

To remove the deep-seated dust, you can use the Scotch method, cut a small piece of duct tape, roll it with the sticky side outside and gently apply it to the microphone hole, and the sticky layer will pull out the impurities that the brush failed to remove.

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The main principle of mechanical cleaning is not to push the dirt deeper, but to extract it outwards, and the movement should be directed from the center of the hole to the edges.

Cleaning with the back cover removed

If the external cleaning didn't work, it might be under the safety net or on the microphone module itself, and it would require partial disassembly of the device to access the insides, a more complex method that requires a suction cup, a mediator (scapula) and a set of screwdrivers.

First, heat the perimeter of the back cover with a hair dryer or a special heating pad to a temperature of 60-70 degrees. This will soften the glue. Carefully suction the edge and, inserting the mediator, go around the perimeter, peeling off the cover. Be careful with the fingerprint scanner plume if it is glued to the cover.

Once you remove the lid, you'll see the main microphone, often located on the bottom board or on the plume, blow the area with compressed air. If you see a foam pad on the microphone, you can carefully remove it, clean the module with alcohol and put the pad back in.

⚠️ Warning: When the lid is removed, the phone has no protection against static electricity.Be sure to touch the grounded metal object or wear an antistatic bracelet before touching the internal components.

In some models, such as the Xiaomi Mi 9 or Redmi Note 8 Pro, the microphone can be soldered directly on the board, in which case the cleaning is done point-by-point, under a magnifying glass, using a microscopic brush and a minimum amount of alcohol.

What to do categorically can not be done

In the pursuit of pure sound, users often make fatal mistakes that turn a repairable problem into a complete destruction of the device. There are a number of myths and harmful tips that can be found on the Internet, but you can not follow them on Xiaomi technology.

Never use a vacuum cleaner to clean the microphone. The powerful flow of air and static electricity generated by the vacuum cleaner can instantly penetrate the thin membrane of the microphone. Also, you should not blow your mouth into the hole - the moist exhaled air will settle inside and cause corrosion.

Avoid using aggressive chemicals like acetone, solvents, window cleaners, which corrode plastic, glue, and can damage the lacquer coating of the board, and only isopropyl alcohol or special electronics cleaners (Contact Cleaner) are safe.

• 🚫 Vacuum: Creates static voltage and too powerful flow.
• 🌬️ Mouth: source of moisture causing contact oxidation.
• 🧪 Acetone: Destroys plastic and protective coatings.

When a microphone replacement is needed

There are times when no cleaning will help, and if after all the procedures, the sound is still quiet, intermittent or completely lost, most likely, the microphone malfunctioned physically, the membrane could burst from a pressure drop or burn from a voltage surge.

The sign of a malfunction can also be cracking, hissing or full noise instead of the voice of the interlocutor, in which case a replacement component is required, and in service centers this procedure is performed quickly, since the microphone module is inexpensive.

If you have soldering skills and a microscope, replace the microphone yourself. However, modern Xiaomi boards use micro soldering, and without experience it is easy to damage the tracks or adjacent elements, in which case it is better to consult the professionals.

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If the cleaning and purging failed within 15 minutes, further attempts may be futile, and the component will likely need to be replaced.