Why do you need to disassemble the Xiaomi Mi 9?
The back cover of the Xiaomi Mi 9 is not just a decorative element, but a complex design that protects the internal components of the smartphone. Most often, users decide to remove it in three cases: replacing the battery (the capacity of which after 3-4 years of operation drops by 30-40%), repairing the camera or speaker, and cleaning from dust and dirt accumulated under the glass. But there are less obvious reasons: for example, replacing the thermal paste on the processor to improve cooling or installing additional protection from moisture.
It's important to understand that disassembling the Mi 9 is not the same procedure as the Redmi budget models, and it uses high-strength adhesive, and the lid is connected to the frame using technology. 3D-And if you've never taken a smartphone apart before, you should go to a service center, because errors can cause plumes to break down or the glass panel to detach.
In this article, we will learn how to open the back cover of the Xiaomi Mi 9 yourself, what tools you will need to do this, and what to look for to avoid turning a smartphone into a brick.
What tools are needed to disassemble the Mi 9?
Without the right tools, it’s almost impossible to remove the Xiaomi Mi 9 cover — you’ll either damage the body or break the latches.
- 🔧 Plastic mediator or suction cup for initial lid suction. Metal tools should not be used!
- 🔥 Hair dryer or thermo-air station - for softening the glue (temperature) 60-80°C).
- 📏 Thin plastic spatula (0.1-0.2 mm) - to carefully separate the cover from the frame.
- 🧲 Magnetic screwdriver. T3 and T5 — screw-off.
- 🧴 Isopropyl alcohol (90%+) — glue-cleaner.
- 🛡️ Protective gloves – to avoid leaving fingerprints on internal components.
If you don't have a thermal air station, you can do with a dryer, but it's important to control the temperature. Overheating above 90°C can damage the battery or detach the screen module is one of the main reasons for the Mi 9 to fail when self-repaired. Also, don't use a knife or screwdriver to lick the lid: the glass on the Mi 9 is thinner than it seems and cracks easily.
Step-by-step: how to remove the back cover
Before starting work, completely turn off the smartphone and remove it. SIM-Follow the algorithm:
- Heat the case. Warm up the back cover evenly with a hair dryer for 2-3 minutes, holding it at a distance of 5-7 cm. Start at the edges where the glue is located. Do not stay in one place for longer than 10 seconds.
- Suctioning with a suction cup. Attach the suction cup closer to the bottom edge (where the USB-C connector is located) and pull up. If the lid doesn't lend itself, warm up for another 1 minute.
- Scapular separation. Put the plastic blade in the gap, and carefully guide it along the frame, separating the glue. Don't push too hard, there are plumes under the lid!
- Check the latches. The Mi 9 has 4 plastic latches at the corners. If the lid doesn't come off, one of them isn't released. Warm up the corner and try again.
When the cover is separated by 2-3 mm, do not remove it completely - first disconnect the battery plume (it is under a black protective film).
- Unscrew 2 T3 screws next to the battery.
- Carefully dent the plume with a plastic spatula and disconnect it.
The smartphone is turned off and removed. SIM-map|At hand all tools (suction cup, shoulder blade, screwdrivers)|The body will warm up evenly with a hair dryer|Battery plume is disconnected before the lid is completely removed-->
⚠️ Attention: If the lid doesn't respond to heat anyway, don't use excessive force, 60 percent of the time it causes the glass to crack or the camera plume to break.
What to do if the lid is not removed?
Even with proper heating, the Xiaomi Mi 9 can stick to the frame.
| Problem. | Possible cause | Decision |
|---|---|---|
| The cover does not respond even after heating. | The glue is dried or replaced with a stronger one (for example, after previous repairs) | Repeat the heat at 80-85°C, use a thin guitar string to cut the glue |
| The glass cracks when underdog | Uneven heating or use of metal tools | Stop disassembling, seal cracks with tape and contact the service |
| The lid is moving, but it's "twitching." | The latches or plumes prevent the complete separation. | Check the corners for non-latching, gently pull the lid up. |
| After removing the cover, the smartphone does not turn on | The battery plume is damaged or the screen module has detached. | Check the connection of all plumes, if necessary, contact the service |
If you notice that the glue under the lid has become hard and brittle (this often happens after 2-3 years of use), it can be softened with isopropyl alcohol. Apply a few drops on the edge of the lid and wait 1-2 minutes. The alcohol will dissolve the glue, but will not damage the internal components.
What happens if you break the battery plume?
How not to damage the smartphone during disassembly: 5 critical errors
Even experienced craftsmen sometimes make mistakes that lead to expensive repairs, and this is not something you can do when disassembling the Mi 9.
- 🔥 Overheat the body. Temperature above 90.°C deforms plastic latches and can blow up the battery. Use a thermometer to control it.
- ⚡ Disable the tails on the eye. Under the lid of the Mi 9 3, the battery, cameras and power buttons!
- 🔨 Press the middle of the lid. The glass is thinner at the edges, the pressure in the center leads to cracks.
- 💧 Use water or acetone. These liquids will damage seals and can cause contact corrosion.
- 🔄 Building a smartphone without cleaning the glue, and the old glue won't keep it tight, and the dust will quickly get in.
One of the most common mistakes is to try to remove the lid without turning off the battery. Even if the smartphone is off, there's still residual voltage on the board. If the plume accidentally closes, it can knock out the power controller. Always disconnect the battery first!
💡
If you're disassembling the Mi 9 to replace the battery, take a picture of all the plumes and screws before you turn off, and when you build it, it saves you 20-30 minutes to find the "extra" parts.
How to assemble the smartphone back: nuances
Building the Xiaomi Mi 9 after disassembly requires as much attention as the process of removing the lid.
- Remove the residues of old glue from the frame and the lids with isopropyl alcohol. Do not use abrasive materials!
- Apply new adhesive. To keep it tight, use 3M 9448A double-sided tape (0.13 mm thick) or B-7000 liquid glue, and apply it with a thin layer around the perimeter.
- Connect the plumes. First, connect the battery plume, then the cameras and the power buttons, make sure they're firmly seated in the connectors.
- Check before final assembly. Connect your smartphone to charge (don't turn it on!) If the charging light goes off, everything is connected correctly.
When you put the lid in place, start at the top edge and gradually press it against the frame as you move down. Don't push hard, the glue must grab on its own. For reliability, put your smartphone under a press (like a stack of books) on top of the lid. 10-15 minute.
⚠️ Note: If the smartphone does not turn on after assembly, but the charging indicator is on, the problem may be in the display plume. Do not try to disassemble it again - contact the diagnostic service.
💡
The use of Xiaomi's original adhesive (MDY-08-ES) guarantees IP53-level leakproofness and dust moisture protection.