Modern smartphones, including popular models from Xiaomi, are designed with minimal gaps between the parts of the case, which creates difficulties when repairing themselves. Users often face the need to replace the battery, screen or charging connectors, and the first step is to carefully remove the rear panel. For the Redmi 9 model, this process requires special attention, since the back cover here is not a removable element, but is glued around the perimeter with a special adhesive composition.
Trying to open the device without preparation can damage the glass, deform the frame, or even break the internal components. In this article, we will discuss in detail how to remove the lid from the phone Xiaomi Redmi 9, what tools will be required and how to avoid common mistakes.
Before you start disassembling, you need to understand that the sealing in budget models is often less good than in flagships, but the glue is used quite aggressive. This means that simple "pinching" here will not help - heat treatment is required. Ignoring this stage can be fraught with cracks in the glass, which will turn a simple repair into an expensive replacement for the entire body.
It's also important to consider that once you remove the lid, you're likely to lose your warranty if it's still in place, but if your smartphone is no longer warranty-worthy or you're the one who caused the damage, disassembling yourself is a great way to save money.
⚠️ Attention: Any actions to disassemble the smartphone you make at your own risk.The author of the article is not responsible for damage to the device during the repair process.
Tools and workplace preparation
The success of the operation depends on the quality of the preparation. You need not only a set of tools, but also a properly organized space. The work surface must be clean, smooth and well-lit so that you can see small screws and plumes. A lost screw or a fallen part can greatly complicate the process of assembly back.
The main tool will be a hair dryer. This can be a professional thermal air soldering iron with a low temperature setting or a regular household hair dryer. Thermophen is preferable, since it heats the point locally, but requires handling skills. A household hair dryer is safer, but you will have to warm longer, about 5-7 minutes, constantly checking the heating temperature.
In addition to the heat source, you will need:
- 🔧 Plastic blade or mediator - for putting the cover without scratches.
- 🧲 Magnetic mat or container - for sorting screws of different sizes.
- 🧴 Clay. B-7000 or T-7000 — Re-fixing the lid after repair.
- 🧤 Thin gloves – so as not to leave greasy marks on the internal components.
Remember to turn off the device before you start work. Even if the phone is discharged, turn off the power via the Settings program menu → About the phone → Shutdown is mandatory. Working with the battery on increases the risk of short circuit if the plumes are accidentally damaged.
☑️ Checking disassembly readiness
Heat treatment of the shell
The most critical stage is heating. The glue holding the Redmi 9's back softens at around 80-90 degrees Celsius. Insufficient heating will cause the glass to crack when you try to tamper with it. Excessive heating can damage the battery or display, so the middle ground is important.
Direct the hot air flow around the perimeter of the back cover. Don't hold the hair dryer in one place for long, especially in the center where the camera is located. Move the device evenly, warming the corners and side faces. The process takes 3 to 5 minutes depending on the power of your hair dryer.
How do you check your readiness? Carefully touch the glass (not the camera!) It should be hot, but not burning to the point of holding your finger. If the glass is barely warm, the glue has not gone away. If it is too hot, let it cool so that it does not damage the internal plastic elements.
Why can't you heat it in the middle?
After warming up, immediately move on to the next step, the glue cools quickly and hardens again, so you need to act quickly, but without sudden movements. If you use a suction cup, attach it now while the glass is hot.
Rear detachment process
When the case is heated, take a plastic shoulder blade or a thin mediator, insert it into the gap between the frame and the glass. SIM-Do not use metal tools such as a knife or screwdriver - they are guaranteed to split the glass or damage the aluminum frame.
Keep your instrument carefully along the perimeter, you'll hear the characteristic sound of the glue peeling off. Move smoothly, don't jerk. If you feel strong resistance, don't push, so the glue in that area hasn't warmed up yet. Go back to the hair dryer and warm up the problem area again.
Pay special attention to the area of the camera module. The glass is often thicker, but the risk of damaging the lenses is high. Go around the camera in a circle, gradually freeing the lid. When the entire perimeter is passed, the lid should easily separate from the main body.
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Use a thin line or string to cut glue. If it's difficult to shovel a shoulder blade, slash the line around the corner and walk around the perimeter with sawing movements, this will reduce the risk of breaking the glass.
Once you remove the lid, put it upwards on the soft cloth with the inside, don't put it on a hard surface with glass downwards so you don't scratch or break it, and now you have access to the insides of the smartphone.
Disconnection of plumes and protection of components
The first thing that catches your eye when you take the lid off is the battery that occupies most of the space and the board is covered by a protective metal plate. In Redmi 9, access to the main connectors is closed by this particular plate, which is screwed up by several screws.
You'll need a cross screwdriver of the right size (usually a PH00 or a PH000) and unscrew all the visible screws on the metal lining, fold them in a prepared container, and then you take the plate off and you open the plumes of the display, the battery, and other modules.
The first thing you need to do is turn off the battery, which is a critical safety rule, find the battery connector and gently disconnect it with a plastic blade, and only after it's turned off can the plumes of the display, the cameras, or other sensors be turned off.
| Component | Location. | Type of connection | Risks. |
|---|---|---|---|
| Battery | Central lower part | Latched plume | Short circuit. |
| Display. | Top of the pay | Wide plume | Breaking the tracks |
| Camera. | Near the camera module. | Thin plume | Optics damage |
| Charging charges | Lower part (separate plume) | schleife | The gust of the plume |
When you disconnect the plumes, don't pull them by the wires. Just peel the plastic connector head. You don't want to touch the metal parts of the connector with your hands, so you don't want to oxidize the contacts. If you're planning to replace the screen, you don't have to turn off the display plume right away, you just have to bend the board aside, but you need to turn off the circuit to be completely disassembled.
Nuances of work with adhesive layer
After successful dismantling, there are remnants of old glue on the frame and on the lid itself, which must be removed before reassembling, otherwise the new gasket or glue will not fall flat and the lid will hang. Use isopropyl alcohol or a special solvent for glue to clean.
Put some liquid on a napkin and clean the perimeter carefully. Don't pour liquid directly onto the smartphone body! It can leak under the display or onto the board, causing corrosion. Old glue can be neatly scraped off with a plastic card or a spatula.
If you haven't bought a new adhesive frame (which is recommended), you'll have to apply the glue manually. Use a tube with B-7000 glue or analog. Apply a thin strip around the perimeter, avoiding getting caught by the camera and speaker. Excess glue exposed to the outside is easily removed with your finger until it freezes.
The glue drys out about 10-15 minutes before the initial fixation, but it gains full strength after 24 hours, so after assembly, don't load the phone, don't drop it, and try not to wet it the first day.
⚠️ Warning: Don't use superglue (cyanacrylate) to fix the lid! It releases fumes that settle on the camera lenses and make the photos cloudy, and also makes the glass brittle.
Assembling and checking functionality
The assembly is done in reverse order. Make sure all the plumes are plugged in before the click and are fixed with the clamping slats. Set up a metal plate and twist all the screws. Make sure that no screws are left out, and none of them are twisted.
Before you finally stick the lid, plug the battery in and turn on the phone. Check the touchscreen, sound, vibration, cameras and fingerprint sensor. If you disassemble the phone to replace the screen and the touchscreen doesn't work, the plume may not be in place.
If everything is working correctly, turn off the device, apply glue to the frame and press the lid. You can use stationery gums to fit evenly, stretching them across and along the body, or put something heavy on top (but not too much so as not to crush the screen).
Leave the phone to dry horizontally. After a day, your Xiaomi Redmi 9 will be ready for active use again. Correctly replacing or cleaning the internal components can significantly extend the life of the device.
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The main secret of success is not to rush when heating and be sure to turn off the battery before working with plumes.