Disassembly Xiaomi Mi 9 Lite: a complete guide with photos and secrets of the masters

Xiaomi Mi 9 Lite (codename pyxis) – popular smartphone of 2019 AMOLED-With a display, a triple camera and a Snapdragon 710 processor, despite being built reliably, owners have to deal with repairs over time, from replacing the battery to cleaning the connectors. Disassembly of this device has its own features - for example, a fragile plume of the fingerprint scanner under the screen or adhesive tape of the battery, which is easy to tear.

In this article, you will find a step-by-step photo instruction, a list of necessary tools, and unique tips for disassembling without damage (for example, how to safely unplug plumes without a soldering iron). We took into account typical beginner mistakes and added proven life hacks from service centers. If you are planning repairs with your own hands, read carefully!

Preparation for disassembly: tools and security measures

Before you start, make sure you have everything you need. Xiaomi Mi 9 Lite does not tolerate brute force - 80% of damage during disassembly is due to inappropriate tools or haste.

• 🔧 Plastic mediators (0.2–0.4 mm) – for separation of the body without scratches.
• 🔥 Hair dryer or thermoplatform (up to 80)°C) - softens the glue under the back cover.
• ⚡ Suction cup (∅40–50 mm – helps to lid after heating.
• ✂️ Tweezers with curved ends - for working with plumes.
• 🔋 Special glue (e.g., glue, B-7000) — reverse-assembly.

Important: Don’t use metal blades – they scratch the aluminum frame and can damage the antenna tracks under the lid. If you don’t have experience, practice on an old smartphone or watch video disassembly on YouTube (look for microscope channels, for example, Zak Reviews).

⚠️ Warning: If you disassemble a phone with a broken display, pre-seal it with tape - glass shards can cut plumes or get into the eyes when heated.

Step 1: Removing the back cover - how not to break the latches

The back of the Mi 9 Lite is glued around the perimeter and is held on 12 plastic latches, and the main mistake of beginners is to try to tear it off without heating, which leads to cracks near the camera or the antenna contacts are torn off.

1. Turn off the phone and remove the tray for SIM-map.
2. Heat the back cover in a circle (2-3 minutes, temperature 70-80 ° C).
3. Push to the bottom of the case (near the USB-C connector) and pull up.
4. Insert a plastic mediator into the resulting gap and lead it along the edge, snapping the mounts.

If the lid doesn't lend itself, heat it up again. Don't force it on the camera area, because there are antenna tracks that are easy to tear, and the lid that is successfully removed must remain intact, without cracks or glue on the edges.

Step 2: Shutting down the battery – why it’s critical

The first thing you do when you take the lid off is to disconnect the battery. The Mi 9 Lite uses a JST 2.0 connector (black, orange tongue) and if you skip that step, shorting the plumes can burn the motherboard.

The battery is glued, but you don't have to pull it out completely -- just lift the edge and unplug the plume with tweezers. Be careful: the contacts are fragile and easy to bend. If the tongue of the connector breaks, use a plastic blade to gently lift the connector.

⚠️ Warning: If the phone was not turned on before disassembly, do not connect the battery back until full diagnosis - this can provoke a re-circuit.

Step 3: Working with motherboard and plumes

The Mi 9 Lite motherboard is mounted on 10 screws of different lengths (from 1.5 mm to 3 mm). Remember the location of each - if you confuse it, you can damage the board or screen. We recommend taking a picture of the process or using a magnetic mat with cells.

Before removing the board, disconnect all the plumes:

• 📱 Display plume (wide, white connector) - the most fragile, hold by the edges.
• 👆 Fingerprint scanner plume (under the screen) – if you break, touch-ID will stop working.
• 🔊 Dynamic plume (small black connector near the connector) USB-C).

Use plastic tweezers to extract the plumes. Metal tweezers can slip through and close the contacts. If the connector does not lend themselves, do not pull the wires, you better heat it with a hairdryer (60 ° C) and try again.

Step 4: Replacing the battery – nuances and errors

The Mi 9 Lite battery (BM4D, 4030 mAh) is glued to double-sided tape, and you need to remove it:

1. Finish the edge of the battery with a plastic spatula.
2. Pull the black band (traction strap) under the battery.
3. If there is no tape, carefully cut the glue with a knife, without touching the body.

The new battery must be original or from a proven manufacturer (e.g. Patona). Cheap counterparts often swell after 3-6 months. Before installation, clean the contacts with alcohol and make sure that there are no pieces of old glue left under the battery.

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If the new battery is not holding charge, check the power controller on the motherboard (the BQ25890 chip next to the battery connector), which is a common cause of rapid discharge.

Step 5: Disassembling the screen - when you can not do without a soldering iron

The Mi 9 Lite (AMOLED, 6.39) is glued to the frame and connected to the board with two plumes: the main (image) and touch (touch). If the screen is broken, but the image is, you can only replace the glass - but this will require:

• 🔥 Thermoplatform (for softening glue).
• 🧲 A blow dryer (for welding plumes).
• 📏 Template for alignment (to make the new screen stand up exactly).

Without experience, it is better to replace the entire module - separation of the glass from the matrix requires an accuracy of up to 0.1 mm. If you decide to repair, use UV-glue to glue the new glass and irradiate it with an ultraviolet lamp (365 nm) for at least 5 minutes.

⚠️ Warning: When replacing the display, be sure to transfer the metal frame from the old screen - it protects the plumes from inflection.

Assembly and testing – how to avoid joints

Collect your phone in reverse order, but take a few things into account:

• 🔩 Screw tighten the cross to avoid skewing the fee.
• 🧹 Dust from the duplicate camera remove compressed air - otherwise the photos will be cloudy.
• 🔋 Connect the battery last when all the plumes are in place.

After assembly, check:

1. Does the vibration work (test: ##0842##)
2. Whether it is determined SIM-map and network (enter #4636## → "Phone information").
3. Does the fingerprint scanner and NFC work?

If something doesn't work, take the phone apart again and check the plumes, most often because of poor contact or bent wires.

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The most common build error is forgetting to plug in the flash plume. If the camera isn't focusing in the dark, check it first.

FAQ: Answers to Frequent Questions