Disassembly Xiaomi Mi 9T: a complete guide with photos, schemes and life hacks

Xiaomi Mi 9T (He's a Redmi. K20 for the global market) is one of the brand's most popular smartphones, released in 2019.Its retractable front-facing camera, AMOLED-The screen and powerful Snapdragon 730 processor made the model iconic, but over time, even such a reliable device can require repairs: from replacing the battery to cleaning the cooling system. If you decide to disassemble the device yourself - this article will help to avoid typical errors and maintain the performance of the gadget.

The Mi 9T has its nuances: a glued case, brittle plumes and the risk of damaging the camera's retractable mechanism. We'll take a look at each step, from tool preparation to assembly, and what parts often fail and how to diagnose them. If you've never taken a smartphone apart before, we recommend that you first check out the FAQ at the end of the article, which answers to the most critical questions.

Preparation for disassembly: tools and security measures

Before you start, make sure you have everything you need, and without the right tools, you risk damaging the case, the plumes, or even the motherboard.

• 🔧 Plastic mediators (2-3 (S) for a careful rear cover.
• 🔨 Screwdriver. T3 and T5 — for the mounting screws of the medium cover and battery.
• 🧲 Magnetic mat or tray – so as not to lose small details.
• 🔥 Dryer or thermo-air station - for softening the glue (temperature 60-80)°C).
• 📱 Suction - will help to lift the cover after heating.
• 🧴 Isopropyl alcohol (90%+) — cleaner.

Also, prepare the workplace: the desk should be clean, well-lit and without static electricity. The use of metal tools (knives, screwdrivers) to lid is strictly prohibited - this will lead to chips and scratches on the aluminum case. If you do not have experience, practice on an old smartphone or watch video disassembly on YouTube (for example, from the Xiaomi Today channel).

⚠️ Warning: Disassembling your smartphone will void the warranty (if it is still valid).Even if you carefully assemble the device back, Xiaomi’s service center may refuse to repair the warranty after finding traces of an autopsy.

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

The back of the Mi 9T is glued around the perimeter and is held on plastic latches.

1. Turn off your smartphone and remove it. SIM-map.
2. Heat the edge of the body with a hair dryer (30–40 seconds on each side) at a distance of 5–7 cm. Do not overheat – temperatures above 80 ° C can damage the battery.
3. With a suction cup, lift the lid at the USB-C connector (there is less glue).
4. Insert a plastic mediator into the resulting gap and carefully lead it along the body, splitting the latches.

The most vulnerable areas are the corners near the power and volume buttons. The latches are thinner and easy to break. If the lid doesn't lend itself, warm up the problem area again. Don't apply force - it's better to spend an extra 5 minutes heating than to get a crack.

After removing the cover, you will see:

• 🔋 Battery with connected plume.
• 📸 Triple main camera (48+8+13 MPP).
• 🔊 Dynamics and vibration motor.
• 📶 Antenna contacts (do not touch them with metal objects!).

Step 2: Disconnect the battery and middle cover

Before you continue, be sure to turn off the battery.

1. Unscrew 5 T3 screws fixing the metal plate over the battery.
2. Carefully tuck the battery plume with a plastic spatula and disconnect it from the motherboard.
3. Check with a multimeter that there is no voltage on the contacts of the battery (should be 0 V).

Now you can remove the middle cover, which hides the motherboard, and it's mounted on 10 T5 screws and a few latches. Be careful with the flexible plumes.

- Display plume (the widest, goes to the top of the board).

- The fingerprint scanner plume (thin, under the battery).

- Retractable chamber plume (fragile, attached to the top of the board).

⚠️ Note: If you understand the Mi 9T If you want to replace the battery, don't rush to pull out the old battery right after you shut it down. In some cases, it can be bloated, because if you try to retrieve it, you risk puncture and fire. If the case is deformed, you better contact the service.

Step 3: Dismantling the motherboard and child modules

The Mi 9T motherboard is mounted on 8 screws (4×T3, 4×T5) and several metal clips. Before you remove it, unplug all the plumes:

• 📱 The display plume (the widest, fastened by a clamping pin).
• 🔋 Battery plume (already disabled at the previous stage).
• 📷 Main camera plume (three thin wires).
• 🎤 Microphone plume and speaker (at the bottom of the board).

Once the plumes are unplugged, gently raise the toll beyond the edges. Don't pull the plugs -- they might come off! Under the board, you'll find:

Vibration motor (NFP-ELV1611A)

- USB-C connector.

- Antenna contacts (don't rot them!)

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If the board isn’t taken out, check if you forgot to disconnect the fingerprint scanner plume – it often hides under the battery and goes unnoticed.

Pay special attention to the retractable mechanism of the camera, which is attached to the top of the body and connected to the board with a thin plume, and if the mechanism is jammed or not extended, the problem may be:

• Pollution of guides (dust, sand).
• Wear gears (requires a replacement mechanism, article: MDY-09-190301).
• Damage to the plume (check with a multimeter).

Step 4: Disassembling the retractable camera is the most difficult step

The retractable camera mechanism is the most vulnerable part of the Mi 9T, and it requires a lot of care to repair it.

1. Remove the top metal plate (3 screws T3).
2. Disconnect the camera motor plume (it goes to the motherboard).
3. Carefully remove the mechanism from the slots, without putting effort to the gears.

If the camera is not moving or jamming, try the following:

• 🧹 Cleaning: blow the mechanism with compressed air and wipe the gears with a cotton swab soaked in isopropyl alcohol.
• 🛠️ Lubricant: Apply silicone lubricant (not oil!) to the guides. WD-40 Specialist Silicone.
• 🔄 Calibration: After assembly, press Volume+ Power for 10 seconds – this will reset the camera settings.

If the mechanism is broken (for example, the gears are crumbled), it will have to be replaced. the original module costs ~ 2,500-3000 rubles, but you can find analogues from third-party manufacturers (for example, For Xiaomi Mi 9T Pop-Up Camera Module on AliExpress).

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Never force the camera to move or move it, it will cause the gears to break, and if the mechanism gets stuck, disassemble and diagnose the cause.

Step 5: Replace the battery when needed

The Mi 9T battery has a capacity of 4,000 mAh (article: MBJ407450) and a life of about 500 charge cycles, after which the capacity drops by 20-30%.

• 🔋 Fast discharge (less than 4-5 hours with moderate use).
• 🔌 Bloating of the body (screen or back cover begins to "pull up").
• 📉 Sharp jumps in charge level (for example, from 50% to 1% per second).
• 🔥 Overheating during charging.

To replace:

1. Unplug the old battery with a plastic spatula. Don't use metal tools, you're at risk of puncture!
2. Clean the seat from the residues of glue with isopropyl alcohol.
3. Apply a new double-sided tape (e.g. 3M 9448A) or B-7000 glue.
4. Connect the plume of the new battery and fix it.

After replacement, be sure to calibrate the battery:

1. Charge your smartphone to 100% and keep charging for another 1 hour.
2. Turn off and discharge until automatically turned off.
3. Repeat the cycle 2-3 times.

⚠️ Warning: If the new battery is rapidly discharged, check the current consumption in sleep mode (should be no more than 50-100 mA). High current indicates a software problem or a malfunction of the motherboard.

Smartphone Builder: How to Avoid Mistakes

The Mi 9T should be assembled in reverse order, but there are a few critical points:

• ⚡ Trains: connect them after fixing the motherboard with screws to avoid distortions.
• 🔩 Screws: Don't pull them over - threading in the Mi body 9T soft and easily broken.
• 📶 Antennas: Make sure the contacts fit tightly with the board (otherwise the network signal will deteriorate).
• 🔋 Battery: before the final assembly, check its operation (turn on the smartphone without the back cover).

After assembly, perform the test:

1. Check the work of the retractable camera (it should move smoothly, without creaking).
2. Test the sensor and display for broken pixels.
3. Make sure all buttons (power, volume) are working.
4. Check the sound in the speaker and microphone.

If the smartphone does not turn on after assembly, possible reasons:

• Unconnected battery plume or display.
• Short circuit on the motherboard (check multimeter).
• A damaged power connector (look for oxidation).

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If new problems arise after assembly (for example, vibration or GPS does not work), chances are you forgot to connect one of the plumes or incorrectly fixed the antenna.

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