How to disassemble Xiaomi Mi 9 SE yourself: instructions with photos and warnings

Xiaomi Mi 9 SE is a compact flagship of 2019, which is still popular today due to balanced performance and high-quality assembly. However, even the most reliable device can require repairs from replacing the battery to cleaning the connectors or recovering from a fall. Disassembly of the Mi 9 SE has its nuances due to the adhesive mounting of the rear cover, fragile glass body and compact interior layout.

This article will help you disassemble the device without damage if you are willing to act carefully and follow the instructions. We will consider the necessary tools, step-by-step process, and unique features of the model that often cause failures when self-repairing, such as the location of the fingerprint scanner plume under the battery. If you have never taken your smartphone apart before, we advise you to first assess the risks or consult a professional.

Preparation for disassembly: tools and security measures

Before you start, make sure you have everything you need. Xiaomi Mi 9 SE is a device with a high density of layout, so you can not do with the "improvised means".

• 🔧 Plastic blades (2-3 (a) - for the separation of the back cover and the slinging of the plumes.
• 🔥 Dryer or thermo-air station - for softening the glue (temperature 60-80)°C).
• ⚡ Suction - helps to pick up the cover after heating.
• 🔩 Screwdriver cross (PH00) five-bladed (Y00) — screw-type.
• 📦 The screw tray – so as not to lose small details (in Mi 9) SE over 15!).
• 🧴 Isopropyl alcohol (90%+) — cleaner.
• 🔋 New glue (bilateral scotch or liquid glue) B-7000) — assemble.

Also, prepare your workplace: a table with good lighting, an antistatic mat (if any), and charge the battery to 30-50%, which will reduce the risk of fire if you accidentally circuit. Don't disassemble the device on the carpet or couch - static electricity can damage the motherboard.

⚠️ Note: If you are looking for the Mi 9 SE To replace the battery, remember that the original Xiaomi batteries have a built-in controller.Using non-original counterparts without calibration can lead to rapid discharge or bloating.

Step 1: Removing the back cover is the most important step

The back cover of the Mi 9 SE is glued around the perimeter, and its glass surface is fragile. Don't try to tamper with it without heating, it will lead to cracks.

1. Turn off your smartphone and remove the tray for SIM-map.
2. Heat the back cover around the edges with a hair dryer for 2-3 minutes, keeping it at a distance of 5-7 cm. Do not overheat - temperatures above 80 ° C can damage the battery.
3. Suction the suction cup onto the bottom of the lid (near the USB-C connector) and pull up. If the lid fails, repeat heating.
4. Insert a plastic blade into the gap, and carefully guide it around the perimeter, separating the glue. Don't use metal tools, they will scratch the body.

Pay special attention to the area around the fingerprint scanner, which is a plume that is easily damaged, and if the lid is tightly removed, don't put too much effort into it: warm up the problem area again.

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

When the lid is removed, the first thing you need to do is turn off the battery. In the Mi 9 SE, it is located at the top and glued to the body. However, before you touch it, find the battery connector on the motherboard (it is usually black with a red marker) and gently disconnect it with a plastic blade.

If you don't turn off the battery before further disassembly, the risk of short circuits when you touch metal parts of the case or screwdriver is more than 70%, which can incapacitate the power controller or even burn the board.

• 🔌 The battery connector is under a metal protective plate (it must be unscrewed beforehand).
• 🔧 The screws that fasten the plate have different lengths - remember their location, so as not to confuse when assembling.
• 🛠️ If the connector is “stopped”, do not pull it by force – moisten the area around it with isopropyl alcohol and wait 10 seconds.

⚠️ Attention: In Mi 9 SE It uses a dual-layer battery (3070 mAh capacity).When replacing it, be sure to check that the new battery has the same controller - otherwise the smartphone will not correctly display the level of charge.

Step 3: Removing the motherboard and child modules

After the battery is turned off, the motherboard can be dismantled, and in the Mi 9 SE, it is mounted on 12 screws of different sizes, and is connected by several plumes:

When collecting fees, be careful with:

• 📸 Main camera plume - it is short and easily breaks with sudden movements.
• 🔊 Nest dynamics - in Mi 9 SE It is soldered and with careless dismantling can come off.
• 📶 Antenna contacts - they are located on the sides of the board and bend under pressure.

💡

Before you completely remove the motherboard, take a picture of its location from several angles, which will help to connect all the plumes correctly when you reassemble.

Step 4: Dismantling the display and touch module

If you need to replace a screen or a sensor, this is the most time-consuming step. In the Mi 9 SE, the display is glued to the frame, and the touch module is integrated into it (OGS technology - One Glass Solution).

• 🔄 Replacing glass separately from the display is impossible - only the entire module is not possible.
• 💧 The glue here is more durable than on the back cover - you will need to warm up longer (up to 5 minutes).
• 📱 The plume of the display is very thin - it is easy to damage when lifting the screen.

Algorithm of action:

1. Heat the display around the perimeter, paying special attention to the corners.
2. Pick up the screen with a plastic spatula on either side and carefully guide it along the frame.
3. Once the screen is separated, do not raise it above 45 ° - the plume may break.
4. Disconnect the display plume from the motherboard (it is fixed with a latch).

⚠️ Attention: In Mi 9 SE There is a notification under the display (LED-If it is not neatly dismantled, it is easy to tear it off, which will lead to the absence of backlight when charging or notifying.

Common Mistakes and How to Avoid Them

Even experienced craftsmen sometimes make mistakes when disassembling the Xiaomi Mi 9 SE. Here are the most common of them and ways to prevent them:

• 🔋 Battery damage during heating → Use a thermal paste or foil to protect the battery while the lid is warmed up.
• 📱 Fracture of the fingerprint scanner plume → Don’t lid the scanner area – start at the bottom edge.
• 🔧 Loss of screws → Use a magnetic tray or stick a scotch with captions on the table for each type of screw.
• 💧 Engagement of alcohol on screen → Apply isopropyl alcohol only on the glue, not on the display itself - it can damage the oleophobic coating.

Another common problem is that the build is not properly built, and the smartphone doesn't turn on, and 90 percent of the time, it's because of:

• Unconnected battery plume or display.
• Distortion of the motherboard (screws are unevenly twisted).
• The debris hits under the power/volume buttons.

💡

If the Mi 9 SE doesn’t turn on after assembly, check the battery and display plume connection first, and 70% of the time, they are the problem.

← How to avoid new problems

Building a smartphone is often harder than disassembling. Here are the key points for the Xiaomi Mi 9 SE:

1. Cover glue: Use a new double-sided scotch or B-7000 liquid glue. Apply it in a thin layer - the excess can be squeezed inside and lock the buttons.
2. Screw them in reverse order, starting with the longest. The Mi 9 SE has 3 types of screws - it's easy to confuse them!
3. Plugs: Make sure all the latches on the connectors are fixed before the click, especially with the display plume and the camera.
4. Check: Before final assembly, connect the battery and check the operability of all modules (camera, speaker, sensor).

If you have replaced the battery, be sure to calibrate:

1. Charge your smartphone to 100% and don’t turn off charging for another 1 hour.
2. Turn off the charging and discharge until it is automatically turned off.
3. Charge again to 100% without interruption.

This will help the controller to correctly determine the capacity of the new battery.

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