Replacement of the bottom buttons on Xiaomi: from disassembly to assembly

The bottom buttons on Xiaomi smartphones are one of the most vulnerable parts of the device, and over time they start to fail, stick or completely stop responding to pressing, especially when models with mechanical buttons (Redmi Note 5/6/7, Mi A2) or touch panels (Mi 9T, POCO F1) are faced with this problem, which can be due to wear of contacts, moisture, mechanical damage or software failures.

Many users mistakenly think that replacing buttons requires professional skills and expensive equipment. In fact, with minimal tools and accuracy, you can do the procedure yourself - the main thing is to follow proven schemes and avoid typical errors. In this article, we will analyze all the stages of replacement, from diagnosing the problem to the final assembly, and give recommendations for the selection of spare parts and tools.

If you’ve never disassembled a smartphone, don’t worry: modern Xiaomi is designed with modular replacement components. However, some models (such as the Redmi Note 10 Pro or Xiaomi 11T) have a more complex design, where the buttons are integrated into the middle frame, in which cases it may require a complete disassembly of the body.

Before you start repairing, make sure that the problem is in the hardware. Sometimes the "failed" buttons are the result of a software failure. Try resetting to the factory settings (Settings → Phone → Reset) or flashing the device through Fastboot. If that doesn't work, start disassembling.

1. Diagnostics of the problem: hardware failure or software glitch?

Touch buttons (such as those on the Mi Mix 2S or POCO X3) often stop working due to firmware failure or damage to the plume connector. Mechanical buttons (Redmi 4X, Mi 8 Lite) usually fail due to physical wear or oxidation of the contacts.

Here's how to check what's going on:

• 🔍 Sensor test: Install the Touch Screen Test app from Google Play. If the buttons don't respond in the test, a hardware problem.
• 🔄 Reboot in Safe Mode: Press the power button, hold off "Stop" until the Safe Mode option appears. If the buttons are running in Safe Mode, it is the fault of third-party software.
• 🔧 Contact Checker: Connect your phone to your PC and execute the command: adb shell getevent -l Press buttons – if there are no events in the log (for example, click on the buttons, KEY_HOME), The signal does not travel at the hardware level.

If all the tests confirm a hardware malfunction, move to disassembly, but remember: on models with IP-certified (for example, Xiaomi 12 Pro or Redmi Note 11 Pro+ 5G), after opening the case, moisture and dust protection is lost.

2.Tools and parts: what will be needed to replace

To replace the bottom buttons with Xiaomi, you need a minimal set of tools. Don't skimp on quality - cheap plastic pickers or screwdrivers can damage the case or plumes.

• 🛠️ Tools: Screwdriver kit PH00 and Y00 (Plastic mediators or guitar mediators (to separate the body); screen suction cup (to remove the display); curved-ended tweezers (to work with small parts). Dryer or thermal air station (for softening the glue on models with adhesive screen mounting).
• 🔄 Parts: New button or entire bottom module (for the Redmi Note 8 Pro, the buttons are assembled with a plume). B-7000 (if the original glue has lost its properties. Alcohol and cotton swabs (to clean contacts).

Xiaomi’s official service centers rarely sell parts retail, so contact trusted suppliers:

⚠️ Note: When buying a button, check its compatibility with your model. For example, the buttons for the Redmi Note 7 and Redmi Note 7 Pro are identical in appearance, but have different plume connectors!

3. Step-by-step dismantling of the smartphone: how to get to the buttons

The disassembly process depends on the Xiaomi model. We will consider a universal scheme suitable for most devices with a removable back cover (Redmi 5/6/7, Mi A1/A2) and monolithic housings (Mi 9, POCO F3).

For models with a removable cover (for example, Redmi Note 5):

For monolithic cases (for example, Xiaomi Mi 10T):

⚠️ Note: On some models (POCO X3 NFC, Redmi Note 9 Pro buttons soldered to the board, which requires a soldering station and experience with microelectronics, and if you're not sure about your skills, you'd better contact the service.

4. button replacement: mechanical vs touch

The replacement process depends on the type of buttons. Mechanical buttons (Redmi 4X, Mi Max 2) are usually a separate module with micro-switches that is attached to the middle frame. Touch buttons (Mi 9, POCO F2 Pro) are most often integrated into the display module or bottom plume.

Replacement of mechanical buttons:

• Remove the old module with buttons (it can be glued or fixed with latches).
• Clear the contacts on the board and the new module with alcohol.
• Set a new button, making sure all latches are in place.
• Connect the plume and check the operability until full assembly.

Replacement of touch buttons:

• If the buttons are built into the display (e.g., on the Mi Mix 3), the entire screen will need to be replaced.
• If the buttons are on a separate plume (like the POCO F1), unplug the old plume and plug in a new one. Be careful - the connectors are very fragile!
• Check that the plume is not clamped during assembly - this can cause a repeat cliff.

⚠️ Attention: On models with AMOLED-screens (Xiaomi 11 Lite, Redmi) K40) Touch buttons are often paired with a display, and trying to replace them separately can damage the matrix!

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If the buttons are "once again" after you change, check the density of the plume, sometimes helping to put a thin strip of insulation tape under it for better contact.

5. Common Mistakes and How to Avoid Them

Even experienced wizards sometimes make mistakes when replacing buttons with Xiaomi, and here are the most common ones and ways to prevent them:

• 🔧 Train damage: Never pull the plume, just hold the edges of the plume. If the connector doesn't detach, check if there's a latch.
• 🔥 Overheating during soldering: If you have to solder a button, use a temperature not higher than 300°C and acid-free flux. Overheating can damage the boardways.
• 🧲 Loss of screws: The screws on Xiaomi are often of different lengths. take a picture of their location before unscrewing or use a magnetic mat.
• 💧 Getting glue on the contacts: When replacing bilateral tape, make sure that the glue does not get on the connectors.

Another common problem is when buttons are broken after assembly, and the reasons may be:

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If the buttons are replaced, check the battery and power plume connection, and often the wizards forget to plug them back in!

6.Assemblying and testing: the final steps

Once you change the buttons, put the phone back together in reverse order, and pay special attention to the following:

• 🔩 Tighten screws: Don't pull them over, it can damage the board. Use a dynamometer screwdriver (optimum torque is 0.3-0.5 N·mm).
• 🔌 Connecting plumes: Make sure all connectors are latched. On some models (Redmi Note) 8T) The button plume goes along with the charging port plume - check its connection.
• 📱 Test before final assembly: Connect the battery and turn on the phone without closing the case. Check all buttons, speaker and microphone (they can be on the same plume).

If everything is working properly, close the case. For models with adhesive screen mounting (Xiaomi 12, POCO F4) use a new glue or double-sided 3M 9448A Scotch. After assembly, check the leakage - if the phone had IP53 protection, after self-repair it will be lost.

⚠️ Note: On models with infrared port (Redmi Note 10, POCO M3) After disassembly, you may need to calibrate the sensors. Use the engineering menu (#4636##) or the Sensor Test app.

7. Alternative solutions: if the replacement did not help

In rare cases, replacing the buttons doesn't solve the problem, which can mean that the malfunction is deeper, like in the button controller on the motherboard or in the firmware.

• 🔄 Fastboot firmware: Sometimes a firmware failure leads to broken buttons. Download the official firmware for your model from Xiaomi's website and run your phone through the Mi Flash Tool.
• 🖥️ Use of the ADB: If the physical buttons don't work, you can emulate the presses on the computer. USB and use the commands: adb shell input keyevent 3 # Home button adb shell input keyevent 4 # Back button"
• 📱 Program buttons: Install the Button Mapper or Navigation Gestures app to reassign actions to other gestures or virtual buttons.

If none of these methods worked, the problem could be damage to the motherboard, which would require a DC Power Supply and oscilloscope diagnostic.

FAQ: Frequent questions about replacing buttons with Xiaomi