Disassembly Xiaomi Mi 9 SE: step-by-step guide with photos and nuances

Why to disassemble Xiaomi Mi 9 SE and what you need to know before you start

The Xiaomi Mi 9 SE, launched in 2019, remains popular with users due to its compact size, powerful hardware and affordable price in the secondary market. However, over time, even reliable equipment requires repairs, from replacing the battery to cleaning the connectors or diagnosing the motherboard. Disassembling the device is the first step in any repair, but without knowing the nuances, it is easy to damage fragile plumes or break the mounts.

This guide will help you disassemble the Xiaomi Mi 9 SE as safely as possible, avoiding typical errors. We will describe in detail each step from tool preparation to removing the back cover and removing the internal components. We will pay special attention to the weak points of the model: a thin glass case, battery glue mount and fragile plume connectors. If you have never taken your smartphone apart before, we recommend reading the article to the end first, this will save time and nerves.

⚠️ Important: Disassembly of the smartphone Xiaomi Mi 9 SE It cancels the warranty (if it is still valid), even careful intervention can damage the dust-water protection (IP53), So weigh the risks before starting the job.

Training: tools and materials

The Xiaomi Mi 9 SE will require specialized tools to disassemble, and the use of improvised tools (knives, screwdrivers of the wrong size) is almost guaranteed to result in scratches on the body or the failure of the screws.

• 🔧 Torx-bit screwdriver set T3, Torx T4, Phillips PH00 pentalobe P2 (screw-tray SIM-map).
• 📱 Plastic mediators or shoulder blades (2-3 (S) to separate the back cover. Metal tools may not be used!
• 🔥 Dryer or thermo-air station with temperature control (optimum 60-80)°C) for softening the glue.
• 🧲 Magnetic mat or screw container (so as not to lose small details).
• 🔋 Isopropyl alcohol (90%+) and lilac-free wipes for cleaning contacts.
• 🛠️ Suction (optional) for initial liding.
• 📦 Tweezers with thin ends for working with plumes.

If you are planning to replace the battery, pre-prepared a new battery with adhesive strips (such as the original BH41 or Baseus analog).Other repairs may require a thermopast (such as the Arctic MX-4) or double-sided tape to fix the components.

⚠️ Warning: Do not use a hair dryer instead of a thermo-air station - it does not give accurate temperature control.°C can damage the screen or battery. If the hair dryer is not available, the alternative is to heat the lid on the heating battery (10-15 minutes), but it is less efficient.

Step 1: Turn off and remove the back cover

Before disassembling, be sure to turn off the smartphone and remove the tray. SIM-To do this, use a paper clip or a special key inserted into the hole on the side:

1. Heat the body. Turn the dryer on at a minimum temperature (60-70 °C) and evenly warm the back cover for 2-3 minutes, paying attention to the edges. The glue under the lid will soften, and it will be easier to separate.
2. Take a plastic mediator and gently insert it into the gap between the lid and the frame (start with the lower left corner where the antenna is located). If the lid does not respond, warm up the area again.
3. Separate the cover. Smoothly move the mediator along the edge, separating the cover. Don't force -- if the resistance is too high, warm up the problem area again. The cover is held on the glue and latches, so it's important to act evenly.

✅ Sign of success: You'll hear the characteristic clicks of the latches that are coming off. If the lid is only partially separated, don't pull it by force, you'll better warm up the remaining areas.

⚠️ Attention: Under the back cover of Xiaomi Mi 9 SE If you damage them, you'll get a blemish on your Wi-Fi and cellular signal. When you separate the lid, make sure that the mediator doesn't touch those elements.

Step 2: Battery disconnection

After removing the back cover, the first thing you need to do is turn off the battery to avoid short circuits. In the Xiaomi Mi 9 SE, the battery is glued to the body, and the connector is located under a protective film.

1. Take the protective film off. Carefully tuck the black film over the battery with tweezers or a nail, which is attached to a weak glue and easily detached.
2. Unplug the battery plume. The battery connector is under a metal plate (fixed by a Torx T3). Unplug the screw, remove the plate, and disconnect the plume with a plastic blade. Don't pull the wire!
3. Check disconnect. After disconnecting the plume, check with a multimeter that there is no voltage on the contacts of the battery (should be 0 V).

Critical! If you skip this step and start working with the motherboard with the battery connected, the risk of short circuit (and failure of the power controller) is ~70%. Even if the smartphone is turned off, the battery remains energized!

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If the battery is swelling, don't try to puncture it or bend it! This can cause fire, in which case, immediately dispose of the battery at a special reception point.

Step 3: Dismantling the motherboard and child components

The Xiaomi Mi 9 SE motherboard is mounted on 10-12 screws of different sizes (Torx T3 and Torx T4). Before removing it, you must disconnect all plumes and daughter boards.

1. Photograph the location of the screws. Photograph the board from multiple angles - this will help to properly assemble the smartphone back. The screws in the Mi 9 SE are of different lengths, and it is easy to confuse them.
2. Disconnect the plumes. Start with the connectors: 📸 Main camera plume (under metal plate). 🔊 Speaker and microphone plume (at the bottom of the board). 📱 Display plume (the widest, at the top).

To disconnect, use a plastic spatula, putting the connector on the side.

Fee-free.

⚠️ Attention: In Xiaomi Mi 9 SE And there's a vibrator motor under the motherboard, which is mounted on a weak two-way tape, and when you take the board off, it can stay on the body -- don't lose it!

Step 4: Disassemble the front panel (screen and buttons)

The Xiaomi Mi 9 SE screen is paired with a touchscreen and is attached to the frame on glue and latches. It will require patience and accuracy to remove it, since the display plume is very fragile.

1. Warm up the edge of the screen. Dryer heat the top of the screen (where the plume is located) to 70-80 ° C for 1-2 minutes.
2. Screen separation. Insert the plastic mediator into the gap between the screen and the frame (start at the top right corner). Smoothly drive the mediator along the edge, separating the glue. Do not insert the mediator deeper than 2-3 mm, so as not to damage the plume!
3. Disconnect the plume. After the screen is separated, disconnect the display plume (it is under a metal plate fixed by a Torx T3 screw).

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The most common breakdown in the dismantling of the Xiaomi Mi 9 SE is a break in the display plume. Its replacement costs 30-50% of the cost of a smartphone, so it is better to spend an extra 10 minutes on a neat screen compartment than then look for a donor for repair.

If after the assembly of the smartphone does not turn on, check:

1. Is the battery connected (the voltage at the contacts should be ~3.8 V).
2. Are there any stains in the sleeves (the long ones)?
3. Are all the plumes connected (especially the display and the Power buttons).

Assembly and performance check

The Xiaomi Mi 9 SE is assembled in reverse order, but taking into account several nuances:

• 🔋 The battery should be glued evenly - without bubbles and distortions. Use original adhesive strips or quality double-sided tape.
• 📱 Connect the display plume last so as not to damage it when installing the board.
• 🔧 Screw the screws cross-curl to avoid skewing the board.

After assembly, perform the test:

1. Check the sensor (if the screen responds to touches at all angles).
2. Test the cameras (main, front and wide-angle).
3. Make sure the buttons, speakers and microphones are working.
4. Check the charging (plug the charger and make sure the current is running).

⚠️ Warning: If after assembly, the smartphone overheats or discharges quickly, chances are you forgot to apply the heat paste to the processor.In Xiaomi Mi 9 SE It's under a metal screen on the board -- you have to take it off, put a new layer of pasta on it, and put it back in place.

FAQ: Frequent questions about the dismantling of Xiaomi Mi 9 SE