The Xiaomi Mi 9 is a challenge that owners face when replacing a battery, repairing a camera, or cleaning from dust. The back of this device is mounted not only on the latches, but also on the adhesive layer, which complicates the process. Incorrect dismantling can lead to cracks in the glass, damage to the plumes or tearing off antenna contacts.
In this article, you will find a step-by-step guide to the Mi 9 design, a list of necessary tools and unique adhesive mounting tips that are not found in standard guides, and we will also look at common mistakes and ways to avoid them, from overheating the body to misuse of the mediator.
If you’ve never taken a smartphone apart before, we recommend you to carefully study all the sections: there are no universal solutions, and every step is important to keep the device running.
Preparation for analysis: tools and conditions
Before you start removing the lid, make sure you have everything you need. Xiaomi Mi 9 requires care due to the fragile lid. 3D-There's a little bit of glass and a little plume underneath the lid:
- 🔧 Plastic mediator (0.15–0.2 mm) – to separate the lid and the body. Metal tools can scratch the frame.
- 🔥 Hair dryer or thermo-air station - for softening the glue (optimum temperature: 70-80)°C).
- 🧲 Suction - helps create an initial effort to separate the cover.
- 📏 Thin spatula or spooger - for careful slapping of latches.
- 🔋 Isopropyl alcohol (90%+) — for removing glue residues after disassembly.
- 🧴 Double-sided tape or glue B-7000 — If you plan to reassemble the lid.
Also prepare the workplace:
- 🪑 Work at a table with good lighting – it is better to use a desk lamp.
- 📱 Put soft cloth (such as microfiber) under your smartphone so as not to scratch the screen.
- 🔌 Turn off the device and remove it. SIM-map from the tray - this will prevent short circuit.
⚠️ Warning: Do not use a household hair dryer at maximum power - the flow of hot air can warp plastic elements inside the case. Keep the hair dryer at a distance of 5-7 cm from the smartphone.
If you don’t have experience with electronics, practice on an old smartphone or watch Mi 9 video disassembly on YouTube (such as Xiaomi Repair or Fixez channels), which will help you understand where the latches are located and how to correctly direct the mediator.
Step-by-step: how to remove the cover from Xiaomi Mi 9
The process of removing the lid consists of several steps. Follow the instructions strictly in order to avoid damage.
1. Heating of the shell
The glue that the lid is glued to becomes elastic when heated. Turn on the hair dryer and evenly warm the back of the smartphone for 2-3 minutes, paying special attention to the edges. Do not hold the hair dryer in one place for longer than 5 seconds.
Check the temperature of the case with your hand — it should be warm, but not hot. If the smartphone overheats, it can damage the battery or display.
2. Suction lid separation
Apply a suction cup to the bottom of the lid (near the USB-C connector) and pull up slightly. The goal is to create a small gap between the lid and the body. If the suction cup doesn't hold, warm up the place again.
Once you have a crack, insert a plastic mediator into it and gently run it along the edge, separating the latches. Don't try to tear the lid off right away, it can damage the plumes.
Heat the entire perimeter of the lid |
The mediator is inserted into the slot at an angle of 30°|
Suction cup fixed on flat surface |
The plumes do not reach behind the lid (check visually)-->
3. Careful removal of the lid
Once the perimeter latches are separated, slowly lift the lid, starting at the bottom. Be careful: the top of the Mi 9 contains fingerprint scanner plumes and antenna contacts, which are easy to tear off if you pull the lid sharply.
If the lid doesn't respond, warm up the problem areas again. Don't use excessive force, you'd better repeat the heat.
| Phase | Action. | Possible errors |
|---|---|---|
| Heating. | Warm up the hair dryer cover for 2-3 minutes | Overheating (deformation of the body), uneven heating (glue remains solid) |
| Suction suction | Suction + mediator to create a gap | Too much pulling force (cracks on the glass) |
| Removal of the lid | Gradual separation from the lower edge to the upper | Sharp movement (breaking plumes), ignoring latches |
| Checking the plumes | Visual Integrity Examination | Lack of inspection (hidden damage) |
⚠️ Warning: If you see the fingerprint scanner plume is off after the cover is removed, don't try to solder it yourself. In the Mi 9, this plume is very thin and requires professional equipment to repair it.
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If the lid is not held in place after removal, use paint tape for temporary fixation, this will prevent accidental closure of the contacts during further disassembly.
What to do if the lid is not removed?
Sometimes even after heating the cover Xiaomi Mi 9 does not respond.
- 🔥 Underheated, the glue is not softened. Reheat, paying attention to the corners.
- 🔧 With a very dry glue, if the smartphone was used in high humidity, the glue could harden.°C, but not longer than 1 minute.
- 🛠️ Deformation of the case - if the device fell, the latches could bend. Try to gently press the lid in the latches, while simultaneously poking the mediator.
If the cover is still not removed, try the "line" method:
- Take a thin nylon thread (such as a guitar string or fishing line).
- Put it in the gap between the lid and the body.
- Carefully thread back and forth as if you were cutting glue, a method that requires patience but minimizes the risk of damage.
If none of these methods worked, it's possible that the lid was glued to the factory using two-part glue, and in this case, you should go to a service center, because if you try it yourself, you can cause permanent damage.
What to do if the cover is broken when removed?
How to properly seal the lid back?
After repair or cleaning, the lid needs to be fixed back. In the Xiaomi Mi 9, factory adhesive often loses its properties after the first removal, so a replacement will be required.
- 🧴 Clay. B-7000 — It's a versatile electronics option, and it's applied in a thin layer around the perimeter of the lid.
- 📏 Double-sided scotch 3M (0.2 mm thickness – convenient for beginners, as it does not require time to dry.
- 🔥 Thermoclee - used in service centers, but requires a special pistol.
Instructions for bonding:
- Clean the edges of the case and cover from the old glue with isopropyl alcohol and a lilac-free wipe.
- Apply new glue or scotch with a discontinuous line (not solid!), leaving gaps for air to exit.
- Carefully press the lid, starting from the top (where the plumes are located), and gradually descend down.
- Fix the lid with rods or heavy books for 10-15 minutes (for glue B-7000 will require 1-2 hours of complete drying).
After gluing, check:
- 📶 The antennas (are there any interruptions to the signal).
- 🔋 Charging over a wireless network (if supported).
- 👆 Fingerprint scanner sensor.
⚠️ Attention: If after assembly, the smartphone became worse to catch the network, most likely, the antenna contacts on the lid do not fit tightly to the body.
Common Mistakes and How to Avoid Them
Even experienced craftsmen sometimes make mistakes when disassembling the Xiaomi Mi 9, and here are the most common ones and ways to prevent them:
| Mistake. | Effects of consequences | How to avoid |
|---|---|---|
| Use of metal tools | Scratches on the frame, short circuit | Use only plastic mediators |
| Overheating of the shell (>90°C) | Deformation of plastic, battery damage | Control the temperature with a thermometer |
| Sharp compartment of the lid | Breakage of the print scanner or antenna plumes | Separate the cover slowly, starting at the bottom edge |
| Ignoring the plume check | Hidden damage that will appear later | Visually inspect the plumes after removing the lid |
| Applying too much glue when assembly | The glue is squeezed inside the case, hits the board | Apply the glue with a thin layer with gaps |
Another common problem is that the seal rubber around the chamber is damaged, and if it breaks, dust and moisture will leak into the body, and when disassembling, gently tuck the rubber into a thin blade and remove it with the lid.
If you notice that after the assembly of the smartphone began to overheat, check:
- 🔋 Is the battery installed correctly (there should be no gaps).
- 🔌 Did not get glue on the charging contacts or the motherboard.
- 🌡️ Has not deformed the heat-dissipating gasket on the processor.
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The most vulnerable part of the Xiaomi Mi 9 when disassembled is the plume of the fingerprint scanner, which leads to a loss of functionality of the sensor, and repair costs 30-50% of the cost of the smartphone.
When is the best time to contact the service?
Not all breakdowns can be repaired by yourself. Contact the service center if:
- 🔧 You’ve never taken your smartphone apart and are afraid of damaging the Mi 9.
- 💥 The lid cracked when trying to remove, and the cracks are deep.
- 📡 After assembly, the network or Wi-Fi signal is lost (probably damaged antenna contacts).
- 🔋 The battery is swelling - it is dangerous for health!
- 🖥️ Artifacts or stripes appeared on the screen after disassembly (possibly damaged board or display plume).
The cost of dismantling Xiaomi Mi 9 in the service ranges from 800 to 1500 rubles (depending on the region), which is inexpensive compared to the risk of damaging the smartphone in the amount of 10-20 thousand.
If you do decide to disassemble the device yourself, take a picture of each step on the phone, which will help you to properly assemble the smartphone back and not forget where the screws were installed.