Disassembly Xiaomi Mi 9: a complete guide with photos and nuances

Why to Disassemble Xiaomi Mi 9 and What to Know Before Starting

Smartphone Xiaomi Mi 9, released 2019 The company is still popular among users thanks to its powerful hardware (Snapdragon processor). 855, 6/8 GB RAM) and quality AMOLED-But over time, even a machine that's so reliable can require repairs, from replacing the battery to cleaning the connectors or recovering from a fall, and disassembling the device is the first step in any repair, but without knowing the nuances of the Mi design. 9 easily damage fragile plumes or adhesive base of the screen.

This guide will help you disassemble the Xiaomi Mi 9 without the risk of failure, taking into account the features of the model: hidden latches under the back cover, the location of flexible plumes and potential “traps” (for example, a glued battery).We will describe in detail each step from tool preparation to removal of the motherboard, and also point out critical moments where 90% of users make mistakes (for example, when disconnecting the battery without preheating).

Important: disassembling your smartphone is warranty-free (if it's still valid) and requires care. If you've never repaired your electronics, you'd better go to a service center. But if you decide to do it yourself, follow the instructions Step-by-step, without missing points.

Training: tools and materials

To disassemble the Xiaomi Mi 9 will need specialized tools — a regular screwdriver and knife will not be enough.

• 🔧 A set of plastic blades (preferably with pointed ends) - to separate the lid and the body.
• 🔥 Dryer or thermo-air station (power of at least 500 W) - for softening the glue under the back panel.
• ⚡ Suction cup (diameter 5-7 cm) - will help to nuke the screen after heating.
• 🔩 The screwdriver. PH00 — motherboard screw.
• 🧴 Isopropyl alcohol (90%+) — glue-residue.
• 📦 Magnetic mat or container – to avoid losing small details.

Also prepare the workplace: a desk with good lighting, an antistatic mat (if any) and spare parts (like a new battery or plume if you're planning a replacement).The Xiaomi Mi 9 has brittle flexible cables, so avoid static electricity and metal surfaces.

⚠️ Warning: Do not use metal blades or knives to lid the lid! They will damage the antenna lines on the back, which will lead to deterioration of the Wi-Fi signal and the lid. 4G.

Step 1: Removing the back cover

The back of the Xiaomi Mi 9 is glued all over the perimeter, so you can't just shovel it with a blade. You'll need heat to soften the glue. Here's a step-by-step algorithm.

1. Turn off your smartphone and remove the tray for SIM-cards (use a paper clip or special key).
2. Heat the back cover with a hairdryer for 2-3 minutes, keeping it at a distance of 5-7 cm The temperature should be about 60-70 ° C (do not overheat so as not to damage the battery!).
3. Put the lid on a plastic blade starting at the lower left corner (there is less risk of damaging the plumes), insert the shoulder blade 1-2 mm and carefully lead along the edge.
4. Disconnect the latches: after passing the perimeter, the lid should separate, but it is held by two latches at the top (near the camera). Lift the lid at a 45° angle.

If the lid doesn't respond, repeat the heat for another 1-2 minutes. Don't force it, it can break the plastic clips inside the case. Once you remove the lid, you'll see the battery, motherboard and camera plumes.

Is the smartphone off?|Is the tray removed? SIM-map?|Will the body be heated with a hairdryer?|Are plastic shoulder blades ready?-->

⚠️ Note: On the Xiaomi Mi 9, there are antenna contacts under the back cover. If you damage them with a metal tool, signal reception will deteriorate. NFC Bluetooth.

Step 2: Shutting off the battery

Before any manipulation of the internal components, be sure to disconnect the battery, which will prevent short circuit and damage to the motherboard. In the Mi 9, the battery is glued, but its power plume is easily accessible.

Instructions:

1. Find the battery connector, which is located at the bottom of the board, next to the USB-C port, a black connector with an orange or red wire.
2. Carefully put a plastic spatula on the connector and unplug it from the board.
3. Check with a multimeter (if any) that the voltage on the battery contacts is 0 V.

If the battery is swollen (as seen by the deformation of the lid), do not try to pierce or bend it. In this case, it is better to contact the service. To replace the battery, you will need to remove the glue under it, we will talk about this in the next section.

Step 3: Removing the motherboard

The Xiaomi Mi 9 motherboard is mounted on 12 screws of different sizes (noted in the photo below).

• 📸 Main and front camera plumes (at the top of the board).
• 🔊 Dynamics and microphone plume (bottom, next to) USB-C).
• 📱 Display module plume (under metal screen).
• 🔋 Charging controller loop (unless it has been previously disabled).

Once the plumes are unplugged, unscrew all the screws (use a magnetic screwdriver to keep them safe) and gently raise the edge charge. Don't pull the connectors! The board is also held by two plastic clips at the top - they need to be bent slightly with a spatula.

⚠️ Note: The Mi 9 board has a chip installed NFC (If you're not tidy, it's easy to rip off the board, and it'll lead to a non-working contactless payment.

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Take a picture of the location of the plumes and screws before removing the board, which will help to properly assemble the smartphone back, especially if the repair took several days.

Step 4: Replace the battery (optional)

If the purpose of disassembly is to replace the battery, after the fee is removed, you have to remove the old battery. In the Xiaomi Mi 9, it is glued to high-strength double-sided tape, so you will need:

1. Heat the battery with a hair dryer to 50–60°C for 3–5 minutes.
2. Fill the battery with a plastic card or a special battery tool. Start at the edge where there are no board components.
3. Remove the glue residue from the case with isopropyl alcohol.
4. Install a new battery, pre-removing the protective film with the base adhesive.

Important: the new battery must be original or certified (e.g. from ZMI or Baseus); cheap analogues may swell or not hold a charge; after installation, connect the battery plume to the board and check the voltage with a multimeter (should be 3.7-4.2 V).

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Never use metal tools to remove the battery! The risk of short circuit and fire is extremely high.

Step 5: Disassemble the screen (if necessary)

The Xiaomi Mi 9 screen is one of the most vulnerable, requiring replacements when cracks, a broken touchscreen or pixels are broken, but disassembling the display module is more difficult than replacing the battery, due to fragile plumes and perimeter glue.

Procedure:

1. Heat the screen with a hair dryer (60-70°C) for 3-4 minutes. Start at the edges.
2. Put a suction cup on the display (stick it to the bottom of the screen where there are no sensors) and pull evenly, without jerking.
3. Disconnect the plumes: Display plume (wide, center board); fingerprint sensor plume (thin, right); front camera and sensor plume (top).

Remove the metal screen module

When installing a new screen, use a new adhesive side (you can buy it with a display). Before assembly, check the touchscreen and display - connect the plumes and temporarily turn on the smartphone (without fixing the screen).

Assembly and performance check

The Xiaomi Mi 9 is assembled in reverse order, but with a few nuances in mind:

• 🔌 The plumes must be tightly connected, without skewing. Check every connector on the board, it must not be bent.
• 🔩 Screw the screws cross-cross to avoid skewing the board!
• 📱 Stick the screen from the top (where the sensors are located). Use a press (such as a heavy book) to press evenly.
• 🔋 Battery before the first charge discharge to 20% and charge up to 100% 2-3 times to calibrate the controller.

After assembly, turn on the smartphone and check:

• Does the touchscreen work (take the test in Settings → Display → Sensor Test).
• Are the cameras correct (take a photo on the main and front).
• Does the network catch (check 4G, Wi-Fi and Bluetooth).
• Does NFC work (try paying contactlessly)

⚠️ Warning: If the phone doesn't turn on after assembly, check: Is the battery plume connected, is the contacts on the board closed (check for foreign objects). Is it installed correctly SIM-card (sometimes it blocks the inclusion).

FAQ: Frequent questions about the dismantling of Xiaomi Mi 9