The Xiaomi Mi 9A (also known as the Mi CC9e in some regions) is a popular mid-range smartphone with good hardware, but like any appliance, it doesn’t last forever. Over time, you may need to replace your battery, display, charger, or even motherboard. However, disassembling this device has its own nuances: a fragile fingerprint scanner plume, battery glue, and a thin plastic case that is easily damaged. In this article, we’ll detail how to disassemble the Xiaomi Mi 9A on your own without turning it into a pile of plastic and glass.
Before you start the screwdriver, consider your strength: if you've never taken your smartphones apart, you'd better practice on an old device or go to the service. The main difficulty in disassembling the Mi 9A is the neat compartment of the rear cover, which is glued around the perimeter, and working with fragile plumes. Also note that after disassembly you lose the official warranty (if it still works).
Preparation for disassembly: tools and security measures
Without the right tools, it is almost impossible to disassemble the Xiaomi Mi 9A. Here's what you'll need:
- 🔧 Set of screwdrivers (cross-haul) PH00, flat 1.5 mm, five-pointed Y0.6 screw-tray SIM)
- 🧲 Suction (for suction of the back cover)
- 📱 Mediator or plastic spatula (thin, non-metallic!)
- 🔥 Hair dryer or thermo-air station (for softening glue)
- 🔋 Special glue (e.g., glue, B-7000 reverse-assembly)
- 🧤 Antistatic bracelet (optional but recommended to protect the board)
Also, prepare the workspace: it should be clean, well-lit and without static electricity. Put a soft substrate on the table (like a silicone mat) so that you don't scratch the body. Take a picture in advance of all the steps of dismantling, which will help with the reverse assembly.
⚠️ Warning: Do not use metal blades to lid the lid! They can leave scratches on the frame or damage the plumes. Plastic mediators are safer, but they must also be used carefully.
If you are planning to replace the battery, pre-order the original battery (article: MBJ405600 for the Mi 9A). Cheap analogues may swell or not hold the charge. Also check if you have isopropyl alcohol (90%+) - it will be useful for cleaning contacts and removing glue residues.
Step 1: Turn off and remove the back cover
The first and most important step is to detach the back cover, and it's glued all around the perimeter, so you can't just tamper with it.
- Turn off your smartphone and remove the tray. SIM-cards (use a paper clip or special key).
- Heat the back cover with a hair dryer (~60°C) for 2-3 minutes, evenly leading around the edges. This will soften the glue.
- Suction the top of the lid (where the camera is) and pull up. If the lid doesn't lend itself, warm up the edges again.
- Insert a plastic mediator into the resulting slit and carefully guide it around the perimeter, separating the lid. Start at the upper left corner (there are fewer plumes).
If the lid is not supplanting, do not use excessive force - better warm up the problem area again. On the Xiaomi Mi 9A, the fingerprint scanner plume runs just below the top of the lid, so do not go too deep into the mediator!
He'll warm up the edges with a hairdryer.|I'm using a plastic mediator.|It does not press on the center of the cover (there is a battery)|Fingerprint scanner plume intact-->
Once the lid is removed, carefully put it aside. Underneath it, you'll see:
- Battery (sticked)
- Fingerprint scanner plume (goes to the top of the board)
- Antenna contacts (sides)
- Screws that fasten the metal plate over the board
⚠️ Warning: Don't touch the board with your bare hands - static electricity can damage the chips. If you don't have an antistatic bracelet, at least ground by touching a metal object.
Step 2: Disconnect the battery and remove the metal plate
Before you continue, be sure to turn off the battery.
- Carefully tuck the black battery connector (at the bottom of the board) into a plastic spatula and unplug it. Don't pull the wires!
- Check with a multimeter that there is no voltage on the contacts of the battery (optional, but recommended).
Now you can remove the metal plate that covers the board, and it's mounted on 12 screws of different sizes.
- 🔹 4 screws PH00 (cross-sectional)
- 🔹 6 screws Y0.6 (five-pointed, under the tray SIM)
- 🔹 2 screws T3 (star, near the charging socket)
Remember where the screw was.
What happens if you don't turn off the battery?
Once you remove the plate, you'll see the motherboard, the camera, the speaker and the vibrator, and at this point you can evaluate what needs to be replaced. If the target is a battery, move on to the next step, and if you want to get to the display or the charging connector, you'll have to remove the board completely.
Step 3: Replace the battery (with photos and nuances)
The battery in the Xiaomi Mi 9A is glued to the body, and replacing it requires caution.
- Put a plastic blade on the bottom edge of the battery, where the connector is, if the glue is too strong, put some isopropyl alcohol under the edge of the battery, and it will dissolve the glue.
- Carefully drive the blade under the battery, separating it from the body. Take your time! If the battery is swelling, don't prick it - it's dangerous.
- After extraction, clean the body of glue residues with alcohol and a napkin.
- Install a new battery, plug in the connector and check that the smartphone is switched on, only after that, glue it back to its place (use double-sided tape or B-7000 glue).
In the Mi 9A, the battery is connected to the board not only by a power connector, but also by a thin plume of the thermistor (temperature sensor). If you turn off the battery, don't damage it! If the plume breaks off, the smartphone will show the wrong level of charge or refuse to charge.
| Problem. | Reason. | Decision |
|---|---|---|
| The smartphone does not turn on after replacing the battery | Poor connector contact or damaged thermistor plume | Check the connection of the connector, if necessary, replace the plume |
| A new battery is discharged quickly | Poor battery or uncalibrated controller | Charge to 100%, discharge to 0%, repeat 2-3 times |
| The smartphone warms up when charging | Power controller damaged or battery installed incorrectly | Check the multimeter charging circuit, replace the controller if necessary |
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If the new battery is not holding charge, try resetting the battery data from the engineering menu. To do this, type in the dial ##4636##, select "Battery Information" and click "Clear Statistics".
Step 4: Disassemble the screen and replace the display
Replacing the display with the Xiaomi Mi 9A is more difficult than replacing the battery, as it requires full removal of the board.
- Turn off all the plumes from the board (display, sensor, front camera, speaker) and they're latched, so you can gently shovel them in.
- Unscrew the screws that attach the board to the body (there are about 10, of different sizes).
- Remove the fee and put it aside (better put on an antistatic substrate).
- Now you can take the screen down, it's glued around the perimeter, warm the edges with a hair dryer, and gently tuck it in with a mediator.
When installing a new display, pay attention to:
- 🔧 The sleeves should be flat, without any excesses.
- 📱 Glue – Use a new double-sided scotch to lock the screen.
- 🔊 Speaker – it is glued to the display frame, do not damage it when installing.
⚠️ Warning: If the smartphone doesn't respond to touch after replacing the display, check the touch plume connection. Often the problem lies in poor contact or damage to the plume during installation.
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When replacing the display with the Mi 9A, be sure to transfer the metal frame from the old one to the new screen - it protects the plumes from inflection and ensures the rigidity of the structure.
Step 5: Replace the charging connector, speaker or camera
If the problem is the charging connector (USB-C), speaker or camera, they can be replaced without being completely disassembled.
- 🔌 The charger connector is soldered to the board, you need a solder dryer and experience with microelectronics to replace it.
- 🎤 The microphone and speaker are attached to glue and screws, and the replacement is simple: just disconnect the plume and install new ones.
- 📸 The main camera is also screw-mounted. When replacing, make sure the new module is the same revision (e.g., the new one is the same revision, S5KGM1 main camera).
If you're replacing the charging connector, look at the antenna contacts -- they're close by and easily damaged by sloppy soldering -- and check the integrity of the flexible plume that goes from connector to board.
To replace the front camera, you have to remove the display (as described in the previous step), the camera is attached to the glue and connects through a plume to the board. Be careful - the plume is very thin and easily breaks!
Step 6: Build a smartphone and check the health
The Xiaomi Mi 9A is built in reverse order, but there are several important nuances:
- Check all the plumes – they must be connected to the end (latches must click).
- Apply the new glue to the back cover around the perimeter. Use the B-7000 or double-sided scotch.
- Twisted screws can damage the board.
- Warm up the lid with a hair dryer before final fixation - this will help the glue to grip better.
After assembly, turn on the smartphone and check:
- 🔋 Charging (connect the cable and make sure the current is going).
- 📶 Communications (check work) SIM-maps and wifi).
- 🔊 Sound (speaker, microphone, speaker).
- 📸 Cameras (front and main).
- 👆 Sensor and fingerprint scanner.
⚠️ Warning: If the phone doesn't turn on after assembly, don't panic. Check the battery and board connection. Often the problem is poor battery connector contact or a compressed plume.
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After replacing the battery or display, be sure to reset your settings via Recovery (press Power + Vol+ when turned on).