You pick up the phone to take a voice note or make a call, tap the record button, and the waveform stays flat. You speak louder, move your mouth closer to the bottom of the screen, and still nothing registers. Sometimes the microphone works in the camera app but not on a call; sometimes it started failing the day you had a new screen fitted; and sometimes the phone just cannot hear you in noisy places like a taxi rank or a busy mall. The frustrating part is that the rest of the phone works fine, which means the fault is local to the microphone path.
Microphone failure is one of the most common repair complaints in South Africa, because the primary mic sits on a flex that runs under the screen and is often forgotten when a screen job goes wrong. This guide covers the 30-second resets, the software checks, the South African triggers that catch people out (non-original screens, water in the bottom speaker grille, and dust-clogged mesh), and when the mic module or its flex actually needs a repair.
Modern phones usually have two microphones. The primary mic sits at the bottom of the phone, near the charging port, and handles your voice on calls and voice notes. A secondary mic at the top handles noise cancellation and video audio. Both mics sit on tiny surface-mount modules soldered to the mainboard or on small flex cables that run under the screen. A digital-to-analogue chip on the mainboard converts the audio signal. The chain breaks in only three places: the software handling the audio path (settings, app permissions, background noise), the mic module itself (dirty, damaged, or corroded), or the flex cable that connects it (loose, torn, or forgotten after a screen job).
The five causes below account for most dead microphones on South African repair benches, listed to rule them out in order.
Do the checks in order. End any active call or voicemail check, because a stuck call often holds the mic driver open. Close all camera and voice-memo apps in the background, because they may have the mic locked. Toggle aeroplane mode on for 10 seconds and off again, because the phone sometimes reclaims the mic driver after a network reset. Check that the volume slider for calls is up, because some phones lower call volume silently after a system update. Finally, wipe the bottom speaker grille with a clean, dry, soft-bristle brush or a cotton bud, because a clogged mesh is the silent killer of call audio.
If your voice is still not heard after those five steps, the fault is not a stuck call, a background app, or a dirty mesh. Move to the phone-side fixes below before assuming hardware.
On both Android and iPhone, the first software fix is to check the call volume and the app permissions. Open the recent-apps view and make sure no call, voicemail, or voice memo app is still open in the background. Go to Settings and check that your phone app and any third-party calling app have microphone permission enabled. If a recent system update started the problem, reboot the phone once more, because some audio drivers only initialise correctly after a fresh boot.
For “I can record in the camera app but not on a phone call”, the cause is usually the call app having its own separate audio path or the noise-cancellation feature being too aggressive. Test a regular call after recording a video note. If the video note is clear but the call is not, the phone app or the noise-cancellation software is the fault.
Our guide on what to do when a phone gets water damaged in South Africa explains how to handle a phone that stopped working properly after a splash, including the first 24 hours and the rice myth that does more harm than good.
The fastest way to tell whether the fault is the mic module or the software path is the recording test. Record a 10-second voice memo or video note in a quiet room, then play it back at full volume. If the recording is clear but your voice is not heard on a regular call, the mic hardware is fine and the fault is software – usually the call app, noise cancellation, or a background app holding the mic. If the recording is also quiet or silent, the mic module, its flex, or the bottom grille is the fault.
Two South African factors cause most microphone failures here. The first is the non-original screen job: a replacement using a non-original panel, or rushed without a checklist, can pull the bottom mic flex connector loose or shear the tiny mic module. The phone still works, and the camera may still take photos and record video notes, but normal calls become inaudible because the call audio path goes through a different mic channel. A low-cost shop that skips reseating the bottom mic flex is the most common reason a phone loses its call mic the same day.
The second is dust and lint. In dusty environments – building sites, mining towns, the Karoo, or any street where people eat at outdoor stalls – pocket dust packs into the bottom speaker grille over weeks. The mic still picks up your voice in a quiet room, but you fade out the moment there is any background noise. Cleaning the mesh regularly with a soft brush is cheaper than replacing the mic module later.
A phone that had clear call audio before a screen swap and lost it afterwards almost always has the bottom mic flex disturbed. The flex runs along the bottom edge under the screen bracket, and a screen job that pulls the screen off without loosening the bracket shears the connector. The fix is to reopen the phone, reseat the bottom mic flex, and refit the bracket – a quick job for the original shop. Our guide on touch screen not working causes and fixes in South Africa covers the same forgotten-flex mistake that kills both the mic and the touch sensor.
The primary mic sits at the bottom of the phone, right next to the speaker grille and the charging port, so after a spill the water hits the mic module first. Salt water or sweat is worse: it corrodes the mic pads and the flex trace within hours. The phone may still record video notes in a quiet room for a day, then the mic fades as corrosion spreads. Clean the mic port with isopropyl alcohol, and if the module is pitted, replace it – the part is cheap; the labour is opening the phone properly.
If the resets, the recording test, and a screen-repair reseat all fail, the fault is the bottom mic module or its flex. A drop can crack the module, and corrosion or a torn connector can break the signal path. This is a board-level job: the screen is lifted, the old mic module or flex is unclipped, and a new one is laid down and reconnected. The part is cheap; the labour is opening the phone properly and reseating the bottom mic flex without tearing it.
A phone that cannot transmit voice on a call but can still record a clear voice memo is almost certainly a software fault, not a hardware one. Settings faults stop the call-mic path from working; a dead mic module or flex keeps both the call mic and the recording mic silent.
Local repair shops in South Africa typically charge a diagnostic fee between R250 and R450 to open the phone, confirm whether the fault is software or the bottom mic flex, and quote the rest. Many shops credit the fee back if you proceed with the repair.
A software-only fix, where the shop resets the audio driver, clears a stuck call-app lock, or finishes a half-written update, is often just the diagnostic fee. A bottom mic module replacement, which carries a fresh mic on board, needs the screen lifted and runs R200 to R600, including labour, with iPhones and Samsungs on the higher end. A bottom mic flex replacement, where the cable is corroded or torn, is in the same range, plus a few hundred rand if the bracket must be replaced. If a non-original screen disturbed the bottom mic flex, fitting a correct compatible screen adds the screen price on top.
This article is general guidance based on manufacturer documentation, repair-shop experience, and the sources linked above. It is not a substitute for a professional diagnostic, and it is not a guarantee that any specific phone can be saved. If your phone is under manufacturer warranty, opening it will void that warranty. Always stop work and seek a qualified technician if the phone shows any sign of battery swelling, overheating, or chemical smell. POTATOTECH is a South African retailer of phone parts and repair tools and does not offer a phone repair service.
Why can I record a voice memo, but people cannot hear me on calls?
Because the call mic and the recording mic use different audio paths on most phones, and the call-path mic or its driver is the fault. End any stuck call or voicemail check, close all background apps, toggle Airplane mode, and test a real call again. If the call mic is still silent but recordings are clear, the fault is software – usually the phone app or noise cancellation – and a reboot or a factory reset of network settings usually fixes it.
Why did my microphone stop working after a screen replacement?
Because the primary mic flex runs along the bottom edge under the screen bracket, and a screen job that pulls the screen off without loosening the bracket shears the connector. The fix is to reopen the phone, reseat the bottom mic flex, and refit the bracket – a quick job for the original shop. If the mic died right after a repair, take it back to the shop that did the work, because the reseat is quick for them.
Why can I hear myself on speakerphone but not on the normal call mic?
Because speakerphone uses the top secondary mic, while normal calls use the bottom primary mic. If the top mic works but the bottom mic does not, the fault is local to the bottom mic module, its flex, or the dust-clogged grille. Clean the bottom grille with a soft brush, and if that does not help, the bottom mic module or its flex needs replacement.
Why is my microphone picking up wind noise or background noise on calls?
Because the noise-cancellation software is failing or the bottom mic grille is half-blocked by dust, which lets wind and ambient noise into the mic path. Clean the grille thoroughly, and test again. If the problem started after a system update, it may be a noise-cancellation bug that a later update will fix.
How much does it cost to fix a phone microphone in South Africa?
A diagnostic is typically R250 to R450, often credited back. A software-only fix is often just that fee. A bottom mic module replacement, with a fresh mic on board, needs the screen lifted and runs R200 to R600, including labour, and iPhone and Samsung are higher. If a non-original screen disturbed the bottom mic flex, a correctly compatible screen adds the screen price on top. A mainboard audio-driver repair is the most expensive at R800 to R1500, worth it mainly on higher-value phones.
What should I do if my phone got wet and the microphone failed?
Power the phone off immediately, do not charge it, and dry the outside with a clean cloth. Leave it in a dry, warm place for at least 24 hours before powering it on. Do not put it in rice – rice dust makes the mic port worse. If the mic still fails after drying, the bottom mic module or its flex is likely corroded and needs replacement.
You tap an app and nothing happens for ten seconds, then the whole screen freezes mid-animation. You wait, you tap again, the phone buzzes once and sits there. Sometimes a restart clears it for a day, sometimes it freezes again as soon as you open WhatsApp, and sometimes it started after an update or when […]
You open Maps or your taxi-hailing app, and the blue dot never settles, or it places you three streets away. You stand outside with a clear sky above you, and the phone still takes minutes to lock on, or it locks on and then drops your position into the middle of a field. Sometimes the […]
You pick up the phone to take a voice note or make a call, tap the record button, and the waveform stays flat. You speak louder, move your mouth closer to the bottom of the screen, and still nothing registers. Sometimes the microphone works in the camera app but not on a call; sometimes it […]
