How to change the keyboard on Xiaomi Redmi 9: detailed instructions with photos and nuances

Xiaomi Redmi 9 is a popular budget smartphone, but even it can eventually have problems with the touch keyboard: incorrect input, sticking buttons or a complete failure. If you are faced with this situation, do not rush to carry the phone to the service center. Replacing the keyboard (or rather, the touch module of the display, since there is no physical keyboard in modern smartphones) is a task that can be done at home with tools and patience.

In this article, we will go into detail on the entire process, from fault diagnosis to final testing, how to properly disassemble the Redmi 9, what parts to buy to avoid getting a fake, and how to avoid typical build errors, and we will also look at alternative solutions, for example, when the problem is not in hardware, but in software.

Before you start, consider your strength: repair requires care and attention to detail. If you've never taken your smartphone apart, practice on an old device or watch video disassembly. And remember, disassembling your phone will void the warranty (if it's still valid).

Diagnosis: Is the keyboard really to blame?

Before you disassemble the Xiaomi Redmi 9, make sure that the problem is in the hardware. Often the keyboard "glitch" is associated with software failures.

• 🔄 Reboot the phone. Sometimes it solves the system's temporary freeze.
• 📱 Check the keyboard in safe mode, if it's working properly, it's the third-party app's fault.
• 🔧 Update the software. Go to Settings. → The phone. → Updating the system.
• 🧹 Clear the keyboard cache. Go to Settings for that. → Annexes → Application management → Gboard (or other keyboard) → Memory. → Clear the cache.

If the problem persists after these manipulations, try installing an alternative keyboard (like SwiftKey or Microsoft Keyboard) from Google Play. If it is the same story, it is most likely the touchscreen or the plume connecting it to the motherboard.

Another test: connect your phone to your computer and try to control it through the computer. ADB Or programs like Vysor, and if the keyboard is running from a PC, the problem is the touchscreen or the touchscreen.

⚠️ Attention: If the screen responds to touches unevenly (for example, the right side works and the left side does not), this may indicate damage to the flexible plume, not the touchscreen itself.

What parts to buy for replacement?

Xiaomi Redmi 9 (model) M2004J19G) The keyboard is part of the touchscreen module that's glued to the display, so you can't just replace the buttons, you'll have to change the entire touchscreen (sometimes with the display:

Where to buy:

• 🛒 AliExpress is cheap, but it's a long wait. Look for sellers with ratings above 98% and reviews in photos.
• 🏬 Local service centers are more expensive, but you can check the detail before buying.
• 🌍 Specialized sites like Fixez or iFixit are quality parts, but prices are above average.

⚠️ Note: When buying a touchscreen, check if it comes with pre-applied glue. If not, you will need to buy separately. LOCA-glue and UV lamp for polymerization (or use bilateral tape, but it is less reliable).

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Before buying, check your Redmi 9 serial number in the settings (Settings) → The phone. → Version. MIUI → Make sure the article of the part matches the model M2004J19G (or M2004J19PI for the Indian version).

Tools for replacing the keyboard (touchscreen)

To disassemble the Redmi 9 and replace the touch module, you will need:

• 🔧 Screwdriver kit: cross-haired PH00, flat 1.5 mm, five-pointed Y00 (screw-tray SIM).
• 📱 Plastic mediators (2-3 pieces) - for separation of the body.
• 🔥 Hair dryer or thermo-air station - for softening the glue.
• 🧲 Magnetic mat or container – so as not to lose screws.
• 📏 Suction cups (2 pcs) - for lifting the display module.
• 🧴 Isopropyl alcohol (90%+) — glue-cleaner.
• 🔦 Lupe or magnifying glass - for working with small details.

Also prepare the workplace:

• 🪑 Good lighting (better than a table lamp).
• 📝 Clean surface (table without garbage and dust).
• ⚡ Antistatic bracelet (optional, but recommended).

If you are replacing only the touchscreen (without the display), you will additionally need:

• 💡 UV lamp (for polymerization of glue) LOCA).
• 🧴 Scotch for fixation (e.g, 3M VHB).
• 🧼 Lilac-free wipes.

Step-by-step: disassembly Xiaomi Redmi 9

Before disassembling, turn off the phone and remove it. SIM-Memory card. Follow the instructions:

Step 1: Removing the back cover

The Redmi 9 back is mounted on the latches and glue to remove it.

1. Heat the phone edge with a hairdryer (temperature) ~60°C) for 2-3 minutes.
2. Insert a plastic mediator into the gap between the case and the cover (start at the bottom edge where the charging connector is).
3. Carefully drive the mediator around the perimeter, snapping the clamps. Don't force it, the lid should come off without creaking.

Step 2: Shutting off the battery

After removing the lid, first turn off the battery to avoid short circuit:

1. Unscrew 4 screws that fix the metal plate over the battery.
2. Carefully pluck the plate and remove it.
3. Disconnect the battery plume with a plastic mediator (don’t pull the wires!).

Step 3: Dismantling the display module

Now you need to separate the screen from the body:

1. Unscrew all the screws around the perimeter of the phone (there are about 10-12 pieces).
2. Heat the front of the phone (especially at the edges) with a hair dryer – this will soften the glue.
3. Suction cups lift the display module on one side. Be careful, it's connected by plumes!
4. Disconnect the display and touch screen plumes (they are fixed by latches).

If you're only replacing the touchscreen, you're going to have to separate it from the display.

1. Place the module on a flat surface (screen down).
2. Heat the hair dryer to 70-80°C to soften the glue.
3. Carefully tuck the touchscreen with a plastic card starting at the corner. Try not to scratch the display!

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When disassembling Redmi 9, the main thing is not to rush. The glue under the touchscreen is very sticky, and if you move quickly, you can damage the display or plumes. If the glass does not respond, warm longer (but do not overheat!).

Installation of a new touchscreen

If you have purchased a ready-made module (touchscreen) + Just plug it into the motherboard and assemble the phone in reverse order. If you only replace the touchscreen, follow this instruction:

Step 1: Surface cleaning

Before installing the new touchscreen:

1. Remove the remnants of old glue from the phone's display and frame with isopropyl alcohol and a lilac-free wipe.
2. Make sure there is no dust or villi on the surfaces.
3. If you use LOCA-glue, apply it thinly on the display (not on the touchscreen!).

Step 2: Touchscreen gluing

Carefully place the new touchscreen on the display and align it around the edges.

• If you use LOCA — Place the module under the UV lam for 5-10 minutes to polymerize the glue.
• If you use bilateral tape - tightly press the touchscreen and remove air bubbles (you can roll roll).

Step 3: Connecting the plumes

After bonding:

1. Connect the touchscreen plume to the motherboard (it's usually marked as TOUCH or TP).
2. Then, put the slap on the slap (it should be clicked).
3. Make sure the plume is not bent or stretched.

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If the touchscreen doesn't work properly after assembly (for example, the touches are shifted), you may have misaligned the glass when you glue it together, in which case you'll have to re-adhere.

Phone assembly and testing

Collect the phone in reverse order:

1. Install the display module in place and fix with screws.
2. Connect the battery plume and fix the metal plate.
3. Stick the back cover (you can use a new glue or double-sided scotch).
4. So, turn all the stains (not to be worn).

After assembly, turn on the phone and check:

• 📱 Does the screen respond to touch in all zones (use the sensor test in the engineering menu).
• 🔍 Are there any broken pixels or smears under glass.
• 🔋 Does the phone charge (sometimes during disassembly the connector is damaged).
• 📶 Do sensors (dactyloscope, illumination, approximations) work).

If something's not working:

• Check if the plumes are tight.
• Make sure there is no short circuit anywhere (for example, the curved contacts may touch the body).
• Check the battery connection.

Frequent Mistakes and How to Avoid Them

Even experienced craftsmen sometimes make mistakes when replacing touchscreen.

Another common problem is the shifting of the touchscreen after the touchscreen is replaced, which happens if:

• The glass is curved.
• Used poor-quality glue (touchscreen "floats").
• The plume is not tightly connected.

In most cases, the glass reset helps, and if the problem persists, it could be a defective touchscreen (especially if you bought a cheap part from AliExpress).

FAQ: Answers to Frequent Questions