Replacing buttons on Xiaomi: from diagnostics to soldering – the complete guide

Owners of Xiaomi smartphones sooner or later face the problem of broken buttons – whether it is touch keys (for example, on the Mi A1 or Redmi Note 5) or physical on/volume buttons (POCO F3, Xiaomi 12T). Causes of breakdowns range from banal wear to moisture or mechanical damage after a fall. In this article, we will analyze all the stages of replacement – from fault diagnosis to soldering of new buttons, including the choice of tools and typical mistakes of beginners.

It is important to understand that the process of replacing buttons on Xiaomi differs depending on the model. IP-certification (like Xiaomi 13 Pro) disassembly requires special care due to sealed gaskets, and on budget models (Redmi). 9A) We'll look at universal methods that are suitable for 90% of the brand's devices, and also point out the key differences for flagships and devices with flexible button plumes.

1. Diagnostics of malfunction: why buttons don't work?

Before you disassemble the phone, make sure it's the buttons that are the problem, not the software glitch.

• 🔄 Reboot the device. Sometimes the system freezes blocks the processing of the presses. Hold the power button for 10-15 seconds for a forced reboot.
• 🛠️ Test in Safe Mode. Press the power button, then hold your finger on "Stop" and the option "Safe Mode" will appear. If the buttons are running, it's the third-party app's fault.
• 🔍 Physical injury check. Check the buttons for cracks, backlash, or dirt. On Xiaomi with touch keys (such as Mi Mix 2), check the touch response in the service menu.

If the software methods don't work, use a hardware component test.

1. Enter the code ##4636## (some models run #284##).
2. Select the item "Hardware Testing".
3. Check the button response in the Key Test section.

⚠️ Attention: On devices with MIUI 14+ Service codes can be blocked. In this case, use the application. CPU-Z (section “Tests” or MTK Engineering Mode for Mediatek Processors.

2. Replacement tools: what will be required?

Successful button replacement on Xiaomi depends on the right set of tools.

For models with adhesive display (for example, Xiaomi 11T) additionally require:

• 🔥 Heat station or hair dryer (for softening glue).
• 🧴 Clay. B-7000 (reverse-assembly).
• 📏 Plastic clips (screen fixation during assembly).

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Before disassembling, take a picture of the location of all the screws and plumes – on Xiaomi, they often differ in length and can be confused when assembled.

3. Disassembly of the phone: step-by-step instructions

The disassembly process varies depending on the model, but the overall sequence is as follows:

Turn off the phone and remove it. SIM-map|Remove the cover and the protective glass|Prepare the workplace (clean surface, good lighting)|Charge your phone 30-50% (for post-repair testing)

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Step 1: Removing the back cover

On most Xiaomi (except monolithic cases like Mi Mix 3), the lid is mounted on latches and glue. Warm up the hair dryer of the edge of the body (60-70 ° C) and gently tuck the mediator, starting at the corners. For models with a metal body (POCO F1) may require more effort.

Step 2: Shutting off the battery

When you remove the lid, the first thing you do is unplug the battery plume! Use a plastic tweezer or a mediator. On some models (Redmi Note 10 Pro), the plume is covered with a metal plate, you have to unscrew it.

⚠️ NEVER disconnect the battery plume with a nail or metal - this can cause a short circuit!

Step 3: Access to the buttons

The power and volume buttons on Xiaomi are usually located on a daughter board (flex cable), which is attached to the main board with a connector. Carefully disconnect the plume by pulling the black tongue (not by the wires!). On the POCO X3 models and the newer child board can be soldered - in this case, you will need a soldering station.

4. Replacement of touch buttons (for models without physical keys)

Touch buttons (like those on the Mi A2 or Redmi 6) are film sensors located under the display module, which are more difficult to replace than physical buttons and require a complete disassembly of the screen.

Algorithm of action:

1. Remove the display module (warm up with a glue dryer, use a suction cup and mediators).
2. Disconnect the touch panel plume from the motherboard.
3. Carefully separate the old touch module from the display, which is mounted on double-sided tape.
4. Install the new module by combining the contacts. Press evenly (no distortion!).
5. Connect the plume and test the button response before final assembly.

The cost of a new sensor module for popular models:

• 💰 Xiaomi Redmi Note 8: 800-1200 rubles.
• 💰 Xiaomi Mi 9: 1500–2000 RUB.
• 💰 POCO X3 NFC: 1000-1400 rubles.

⚠️ Note: When replacing touch buttons with Xiaomi AMOLED-Be very careful with your screens (e.g. Xiaomi 12) - it is very easy to damage the matrix when heated unevenly. Use a heat station with precise temperature control (maximum 80)°C for glue).

5. Replacement of physical buttons: soldering and installation

Physical buttons on Xiaomi come in two types:

1. Mechanical (separate buttons on the child board, as on the Redmi 9).
2. Membrane (whole rubber gasket, as on the POCO M3).

For mechanical buttons:

1. Seal off the old button from the childboard using a solder dryer (temperature 320°C) and solder.
2. Clean the contact areas with alcohol and ludular flux.
3. Set a new button by combining the legs with holes on the board.
4. Seal the button to avoid overheating (no more than 5 seconds per contact).

For membrane buttons:

Here, the replacement comes down to replacing the entire membrane. Carefully remove the old pad (it is attached to glue or latches) and install a new one, making sure that all the button holes match. IP-Certification (e.g. Redmi Note 11 Pro)+ 5G) The membrane may be part of a sealed module, in which case the entire unit will need to be replaced.

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When soldering buttons on Xiaomi, use lead-free solder (such as Sn-Ag-Cu) and water-based flux. Lead solder can damage contacts when overheated.

6. Phone assembly and testing

After replacing the buttons, assemble the phone in reverse order, taking into account the following nuances:

• 🔩 Xiaomi often uses screws of different lengths, and if you confuse them, you risk damaging the board!
• 🔌 Make sure all connectors are snapped to the end (clicking should be heard).
• 🔋 Battery.Put the battery in before final assembly and check the button response.
• 🛡️ For sealing models with IP-Xiaomi 13 – Apply a new adhesive layer to the body.

After assembly, perform the test:

1. Check the button response in the menu ##4636## (Key Test section).
2. Make sure the buttons don’t pop or creak.
3. Test the vibration (if it is associated with buttons, as on POCO F4).

If the buttons are not working properly, the possible reasons are:

• 🔌 Bad plume contact (reconnect connector).
• 🔥 Overheating when soldering (check the chain with a multimeter).
• 💧 Getting moisture on contacts (refrigerate your phone 24 hours in rice or silica gel).

7.Typical mistakes and how to avoid them

Even experienced wizards sometimes make mistakes when replacing buttons with Xiaomi.

Pay special attention to models with flexible button plumes (for example, Xiaomi Mi 11). If you do not handle the plume can break at the base - in this case, you will need to replace the entire child board, which will cost 3-5 times more than replacing a single button.

FAQ: Frequent questions about replacing buttons with Xiaomi