Why Xiaomi Redmi 9 is pressed buttons when talking on the phone – all the reasons and solutions

Why does the Xiaomi Redmi 9 screen press buttons when you call?

You're on the phone, and suddenly your smartphone starts opening apps, turning on speakerphones, or even ending a call? This problem is familiar to many Redmi 9 owners -- and it's not always related to a breakdown. Most often, software failures, sensor incorrect settings, or physical factors (such as moisture or damaged glass) are to blame.

In this article, we will look at all the possible causes of phantom screen clicks during a call, from the banal contamination of the display to serious hardware malfunctions. You will learn how to diagnose a problem in 2 minutes, which settings to check first, and when to carry the phone to the service center. And 5 ways to temporarily lock the screen to reach the subscriber without interference.

Spoiler: 70 percent of the time, it's free and undisclosed, and start with the simplest one -- you probably don't even have to go through the settings!

📊 How often do you have a problem with phantom presses?

Only during calls.

With any touch on the screen

After the phone fell

Rarely, but regularly.

1. Check the obvious: dirt, moisture and cover

Before you sin on hardware malfunctions, eliminate external factors. Most often, the Redmi 9 screen itself presses the buttons because:

🧴 Fat marks on the display (especially if you hold the phone with your cheek) the sensor perceives them as touching.
💧 Moisture or condensation under glass (even if the phone did not sink – high enough humidity in the room).
📱 Poor-quality cover with magnets or metal elements that cause interference.
🔥 Overheating (if the phone was lying in the sun or charging during a conversation).

What to do:

Wipe the screen with a dry microfiber (not paper wipes!). Use isopropyl alcohol 70% (not ethanol!) to remove fat.
Take off the case and see if the problem has gone away. If so, replace the accessory with a thin silicone without magnets.
Put your phone in a dry, warm place for 1-2 hours (such as next to the battery) if you suspect moisture.

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If the screen responds to touch without touching, try blowing warm air (dryer at minimum power) on it, and the condensate will evaporate, and the sensor will work normally.

Sensor calibration: resetting touch settings

Redmi 9 touchscreen can become “unjustified” over time – especially if you drop your phone frequently or update your firmware – and this leads to false positives when the system perceives random signals as taps.

Calibration of the sensor is done through a hidden engineering menu. Attention: do not change the other parameters in this menu unless you are sure of their purpose!

Open the Phone |Talk ##6484##|Select Test Mode → Touch Screen Test|Tap Calibration and follow the instructions |Reboot your phone-->

If the code doesn’t work, try an alternative method:

Go to Settings. → The phone.
Click 7 times on the MIUI version to activate the developer mode.
Back to Settings → Additionally. → For developers.
Find the USB debugging option and turn it on.
Connect your phone to your PC and execute the command in ADB: adb shell wm touch calibration reset

What if calibration doesn’t help?

If the problem persists after calibration, check the sensitivity of the sensor in the same engineering menu (Touch Screen Test). If the screen reacts to touches in the wrong places (for example, at the edges) - this is a sign of hardware failure (detachment of the plume or damage to the matrix).

3.Screen settings: Turn off gestures and increase timeout

MIUI has features that can interfere with the call:

👆 Navigation gestures (swipes around the edges of the screen).
⏱️ Short lock timeout (screen goes out too fast).
🔍 Increased sensitivity for gloves.

How to set up:

Turn off gestures: Settings → Screen → Full-screen display → Navigation type → select Buttons.
Increase timeout: Settings → Screen → Sleep and Lock → Lock through → Set 30 seconds.
Reset Sensitivity: Settings → Screen → Touch Sensitivity → Turn off High Sensitivity.

Setting up	Recommended value	Why is it important?
Type of navigation	Buttons (not gestures)	Gestures often work when you touch your cheek.
Screen locking	30 seconds or more	Short timeouts lead to occasional unlocks
Sensor sensitivity	Standard.	High sensitivity increases false positives
Crash-turn	Unplugged.	Turning the screen during a call can press buttons

4. Software glitches: resetting settings and updating MIUI

If the problem occurs after updating the firmware or installing a new application, the software is to blame.

🔄 Restart your phone (hold the power button for 10 seconds).
🗑️ Clear the system cache: Settings → Annexes → Application management → Three points. → Clear the cache of all applications.
📱 Reset the screen settings: Settings → Screen. → Resetting screen settings.
🔧 Update. MIUI: Settings → The phone. → Updating the system.

Last resort: reset to factory settings. Attention: this will delete all data from the phone!

⚠️ Before reset, be sure to make a backup through Settings → Additionally. → Backup and reset, especially keep contacts and SMS — It is hard to repair them.

Instructions for discharge:

Go to Settings → About the phone → Reset settings.
Choose to erase all data.
Confirm the action and wait for the reboot (it will take 5-10 minutes).

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If the phantom presses disappeared after the reset, the problem was in the software. If not, the hardware (the plume, matrix or sensor controller) is to blame.

5.Temporary Solutions: How to Lock a Screen During a Call

While you are looking for a reason, use emergency methods to ensure that the screen does not interfere with the conversation:

🔒 Power button lock: after dialing, quickly press the power button 1 time to turn off the screen. unlock after the call is complete.
📱 Mode in your pocket: turn on the settings → Screen. → The screen will lock when you approach the ear.
🎧 Use a headset: connect wired or Bluetooth headphones – the screen is locked automatically.
🔄 Turn off the sensor: Install the Touch Lock app (available on Google Play) that blocks touches during a call.

Tip for Redmi 9 owners: If you have custom firmware installed (like LineageOS), check the kernel settings. Some builds have a bug with touch handling during calls.

6. Hardware malfunctions: when you need to service

If none of these things worked, it's a hardware problem. Here are the typical Xiaomi Redmi 9 breakdowns that cause phantom clicks:

Malfunction	Signs.	Cost of repair (≈)
Detachment of sensor plume	The screen itself presses the buttons on the edges, reacts to pressure.	1 500–2 500 ₽
Damage to the matrix	Artifacts on the screen, “broken” pixels, uneven backlighting	3 000–5 000 ₽
Failure of the sensor controller	The screen does not respond to touch or is randomly triggered.	2 000–4 000 ₽
Moisture under the screen	Condensate under glass, screen "floats", spontaneous pressing	1 000–3 000 ₽ (cleaning + sealer)

How to check:

Connect your phone to your PC and check if the screen responds to touch in Fastboot mode (keep Power + Volume down when you turn on). If yes, there is a problem with the firmware. If not, it's in the hardware.
Light a flashlight at an angle on the screen: if you see a rainbow hue on the edges - the plume has peeled off.
Check if the behavior changes when you press on different parts of the screen, and if so, the matrix is damaged.

⚠️ Don't try to disassemble the Redmi 9 yourself if you don't have experience! The sensor plume is very fragile and easily damaged if you do not open it properly.

FAQ: Frequent questions about phantom clicks on Redmi 9

Can I repair the screen by myself?

Theoretically, yes, but not recommended. To replace a plume or matrix, you need: Special suction cups and shoulder blades for neat opening. A hair dryer or thermo-air station for softening the glue. A new plume / matrix (cost from 1 000). ₽). soldering experience (if the controller is damaged) Without skills, you risk damaging the board or leaving dust under the screen, which will lead to new problems.

The problem came after the phone fell. What do we do?

It's probably a sensor plume that's broken or a matrix that's cracked. Run the test: Type ##6484##. Select Touch Screen Test. If the screen responds to touches in the wrong places (like edges) the plume is damaged, in which case only replacing the plume will solve the problem: ~2 000 ₽.

After the MIUI update, the screen started pressing the buttons itself. How do you roll back?

If the problem appears after the update, try: Reverse via Recovery: Download the old version of MIUI for Redmi 9. Rename the file to update.zip and place it in the root of memory. Press Power + Volume up to log in to Recovery. Select Install update.zip. Or reset: Settings → Additional → Backup and Reset → Settings. Attention: Running the firmware will reset all data!

The screen only reacts to strong presses. Is it a breakdown?

If the touchscreen is probably worn or the controller is damaged, run a test: If the screen responds to the nail but not to a light touch, the sensitivity problem is (try resetting the sensor settings) If it doesn't respond at all or it works randomly, the plume or matrix is faulty. In the first case, it may help to replace the glass (~3 000 ₽), Second, repairing the matrix (~5 000 ₽).

Can the virus cause phantom pressing?

Theoretically, yes, but highly unlikely. Viruses usually: Show ads; steal data; subscribe to paid services; but they can't physically affect the sensor; if the problem is only during calls, it's 99 percent hardware or software malfunction, not a virus. To check: Install Malwarebytes or Dr.Web Light; scan the phone; remove suspicious applications.