What to do if the sensor on Xiaomi Redmi does not work 7A: from reboot to display replacement

Problems with the touch screen on Xiaomi Redmi 7A — One of the most common malfunctions faced by owners of this budget smartphone: the screen can completely stop responding to touch, “glut” (on your own press buttons or ignore touch), or work only in certain areas. In 70% of cases, the fault is a software failure, but sometimes the cause lies in the physical damage to the touchscreen or plume.

In this article, we will discuss all possible causes of a broken sensor on Redmi. 7A — From the corny contamination of the screen to the serious hardware breakdowns, you'll get step-by-step diagnostic and repair instructions, including how you can use it at home without special tools. And if the problem turns out to be more complicated than it seemed, you will learn how to minimize the risks when contacting the service center.

Before you start repairing, it is important to understand: Redmi 7A It's equipped with a capacitive sensor that responds to the electric field of the finger, which means that it can fail not only from mechanical damage, but also from moisture, static electricity or even incompatible film.

1. Primary diagnosis: how to understand what exactly broke

Before you disassemble your phone or reset your settings, make sure the sensor is the problem, not the software or accessories. Here are 3 key tests to help narrow down the possible causes:

• 🔍 Physical injury check: check the screen for cracks, chips or dents, even a microcrack can disrupt the sensor. Pay special attention to the corners, where the most vulnerable areas of the plume pass.
• 🧤 Test without protective accessories: remove the case, film and glass (if any), sometimes cheap accessories create electrostatic interference, which makes the sensor no longer recognize the touch correctly.
• 🔄 Checking the response to charging: connect the phone to the charger. If the screen "wakes up" and starts to respond to touches, the problem may be the power connector or battery, which indirectly affect the operation of the touchscreen.

If you've done this, you don't have a sensor that's working, then you can move on to the next step, software diagnostics, which is a computer or a second phone.

2. Software failures: reboot, reset and calibration

40% of Redmi sensors are broken 7A — It's a consequence of a software conflict, not a physical failure:

Forced reset

If the screen does not respond, but the phone is turned on (lights, sounds are heard), run a hard reset:

1. Press the Power button for 10-15 seconds until the device turns off.
2. Wait 30 seconds and turn the phone on again.

If you've had the sensor work since the reboot, the problem was that it was a temporary system failure, and if you don't, move on to the next step.

2.2 Resetting settings via Recovery

If the phone is turned on but the sensor is not working, you can try resetting to factory settings via Restore mode, which will delete all data, but often solves the problem:

1. Turn off the phone.
2. Press Power + Volume up until the Mi logo appears.
3. In the Recovery menu, select Wipe Data → Wipe All Data (use volume buttons for navigation and power to confirm).
4. After resetting, restart the device.

If the sensor doesn’t work even in the Recovery menu, the problem is likely hardware.

Calibration of the sensor through the engineering menu

Sometimes the sensor gets knocked down and needs to be recalibrated.

1. Open the Phone app and dial ##6484##.
2. In the menu, select Touch Test.
3. Follow the instructions on the screen (usually touch the dots several times).

If the engineering menu does not open, then the manufacturer has disabled this function for your firmware.

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If the sensor gets worse after calibration (e.g., dead zones) go back to the engineering menu and select Reset Touch to reset the settings.

Hardware problems: plume, contacts and moisture

If the software methods didn't work, it's likely the problem is physical damage. 7A most often:

• 🔌 The touchscreen plume is a thin cable that connects the screen to the motherboard, and it can oxidize, rub, or move away from the connector.
• 💧 Contact oxidation – if the phone fell into water or was in a humid environment, corrosion forms on the board.
• 🔧 Microcracks on glass – even invisible damage can disrupt the sensor.

If you've never done this, you'd better go to the service, but if you decide to do it yourself, follow the instructions.

Checking the touchscreen plume

To get to the plume:

1. Turn off the phone and remove it. SIM-map.
2. Remove the back cover (it is on the latches, but can stick – use a plastic shoulder blade).
3. Unscrew the screws that hold the metal plate over the battery.
4. Carefully disconnect the touchscreen plume (usually located next to the battery connector and marked as Touch). FPC).
5. Wipe the contacts of the plume and connector on the board with alcohol or eraser.
6. Connect the plume back and check the sensor.

Diagnosis of moisture ingestion

If the phone was in contact with the liquid, even if everything was dry, the moisture could have stayed inside.

• The white or green spots are visible on the board.
• The phone is periodically rebooted or warmed.
• The sensor is working in a "snapshot."

To address:

1. Disassemble the phone and dry the fee with a hairdryer (temperature not higher than 50)°C) for 10-15 minutes.
2. Treat contacts with isopropyl alcohol (90% and above).
3. If the oxidation is strong, use a special fluid to clean the boards (such as Contact Cleaner).

⚠️ Warning: Never use acetone or alcohol to clean the board, as these can damage the pavement of the tracks. Also avoid direct hot air (dryer should blow from a distance of 20-30 cm).

4. Problems with firmware and drivers

Sometimes the sensor stops working after you upgrade or install custom firmware, and that's because of a conflict between the touchscreen drivers, and it's going to help you:

4.1. rollback to the previous version of MIUI

If the problem has occurred after the update:

1. Download the stable version MIUI for Redmi 7A (codename pine from Xiaomi's official website.
2. Rename the firmware file to update.zip Put it in the root of the phone’s memory.
3. Go to Settings → About the phone → System update.
4. Click on the three dots in the upper right corner and select Select the firmware file.
5. Please select update.zip and wait for the process to be completed.

4.2 Flashing through Fastboot

If the phone does not respond to touch, but turns on, you can flash it through Fastboot from your computer:

1. Install the Mi Flash Tool.
2. Download Fastboot firmware for Redmi 7A.
3. Turn off the phone and press Power + Volume down to enter Fastboot mode.
4. Connect your phone to your PC and run the firmware through the Mi Flash Tool (select the Clean All option).

If after firmware sensor and did not work, and in the menu Recovery it does not respond - the problem is precisely hardware (damaged touchscreen or plume).

5. When to replace the screen: signs and cost

If all previous methods have failed, it will likely require a replacement of the touch module. 7A The screen and the touchscreen are a single block (OGS-The display, so you have to change everything.

Signs that a replacement is needed:

• 📱 The screen only reacts to a strong press (or does not respond at all).
• 🔍 Physical damage (cracks, wiring under glass).
• 🔄 The sensor works in waves (it reacts, it does not).
• 🔌 After the disassembly, you can see that the plume is intact, but the problem remains.

Costs vary by region and service center.Original parts for Redmi 7A You can find it on AliExpress (screen article: XM-PINE-LCD-Touch), but be careful with Chinese vendors – often unoriginal modules with poor calibration are sent.

⚠️ Note: When changing the screen to Redmi 7A Make sure to check the new module is compatible with your firmware version. Some Chinese screens require additional calibration through the engineering menu, otherwise the sensor will not work properly.

Temporary Solutions: How to Use a Phone Without a Sensor

If repairs are delayed and the phone is urgently needed, you can use alternative management methods:

6.1. Connecting a mouse via OTG

Redmi 7A supportive USB OTG, So it can be connected. USB-mouse:

1. Buy it. OTG-adapter (Type-C) → USB-A).
2. Connect the mouse to the adapter and the adapter to the phone.
3. The cursor will appear on the screen, and you can use the phone as a computer.

Disadvantages: Not all applications work correctly with the mouse (for example, some games or banking applications may block input).

6.2 Control via computer (ADB)

If you have a computer, you can control your phone through ADB (Android Debug Bridge):

1. Install Platform Tools from Google.
2. Turn on the debugging. USB In the developer settings (if the sensor is still at least a little bit working).
3. Connect your phone to your PC and type in the command line: Adb devices to make sure the device is identified.
4. To emulate touches, use the command: adb shell input tap x y where x and y are the coordinates on the screen.

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ADB It allows you not only to control the phone, but also to install applications, take screenshots and even stitch the device around a broken sensor.

Google Voice Assistant 6.3

If the sensor is not working, but the microphone is working, you can use voice input:

1. Say OK, Google (if the function is activated).
2. Say a command like, Open WhatsApp or Call Mom.
3. To navigate the menu, use commands like Back, Home, Open Settings.

7.How to avoid sensor problems in the future

To extend the life of the touchscreen on Redmi 7A, follow these recommendations:

• 🛡️ Use high-quality security glass. Cheap air bubbles can put pressure on the sensor, leading to microcracks.
• 🚫 Avoid overheating. Don't leave your phone in the sun or near heat sources, which speeds up the wear of the plume.
• 💧 Protect against moisture. Even high humidity can cause contact oxidation. Use silicone spray-proof covers.
• 🔋 Don't discharge your phone to zero. Deep discharge can cause sensor controller malfunctions.
• 🔄 Update your firmware regularly. MIUI Often correct bugs associated with the work of touch screen.

If you drop your phone frequently, consider a depreciation case (like the Spigen Tough Armor or Ringke Fusion-X).

FAQ: Frequent questions about the broken sensor on Redmi 7A