Modern smartphones like the Xiaomi Redmi Note 9 Pro are designed with aesthetic integrity in mind, which often implies no visible screws and adhesives. Not only are the rear glass panel removed, but the process of dismantling requires extreme care, as glass is a fragile material that is susceptible to chipping even with minimal mechanical impact.
Before any manipulations are initiated, it is important to understand that opening the case automatically voids the manufacturer's official warranty. If the device is in warranty service, it is wise to contact an authorized service center. However, if the warranty period has expired or damage is not a warranty event, self-repair becomes an economically viable solution. In this article, we will discuss the technical details of safe dismantling.
The challenge is that there's a thermoactive adhesive around the perimeter of the device that securely locks the glass to the metal frame. You can't just pick the lid off without the risk of damaging the internal plumes or breaking the glass itself. Patience and the availability of specialized tools are critical. Wrong actions can cause the display to fail or damage the moisture membranes.
⚠️ Warning: Before starting work, be sure to completely turn off the smartphone. Attempting to remove the cover on the device on can lead to a short circuit if accidental damage to the plumes or battery contacts.
Tools and workplace preparation required
Quality repairs start with the right organization of the workspace. You need a clean, well-lit surface, preferably with an antistatic coating. The absence of dust minimizes the risk of debris falling under a new lid or onto the display matrix. All tools should be laid out in order of use so that they do not look for them while working, when the hands can be busy holding fragile components.
To successfully dismantle the back of the Redmi Note 9 Pro, you will need a toolkit often referred to as an “opening kit.” The basic kit includes a glass suction cup, plastic mediators (scapula), a metal spatula with a thin sting and a dryer to soften the glue. Also highly desirable is a tweezer with curved ends and a set of screwdrivers, since after removing the glass, you will need to unscrew the screws of the internal components.
- 🔥 Hair dryer or thermotable - to heat the adhesive layer to 80-90 degree.
- 🛠️ A set of plastic mediators - for safe layering of glue without scratches.
- 🧲 Magnetic mat or organizer - for sorting screws of different sizes.
- 🧴 Isopropyl alcohol or a special solvent of glue - for the final cleaning of the frames.
Special attention should be paid to the source of heating. Household hair dryer may not provide sufficient temperature, so it is better to use a temperature-adjusted building hair dryer or a special thermoplate. OLED-display matrix or battery, so temperature control is a critical stage of preparation.
☑️ Preparation for repairs
Technology of heating and softening of glue
The adhesive layer used by Xiaomi is a polymer that changes its physical properties when heated, is hard and elastic at room temperature, but becomes viscous and easily detachable when a certain temperature is reached, and the main task at this stage is to warm the perimeter of the device evenly without creating local overheating points.
Turn on the dryer and set the temperature to around 100 degrees Celsius. Direct the hot air flow to the ends of the smartphone, paying special attention to the corners where the glue layer is usually thicker. Keep the dryer at a distance of 3-5 centimeters from the surface. The heating process takes 2 to 5 minutes depending on the power of the equipment. Periodically touch the glass with your finger (caution!) to estimate the temperature - it should become hot, but not scalding.
It is important not to overheat the central part of the back cover, where the logo and sensors are located, as plumes can pass under them. Focus on the perimeter of the frame. If you use a thermal table, put the phone down on a preheated surface (about 80 degrees) and leave for 5-7 minutes, which will ensure the most uniform heating over the entire area of contact.
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Use an infrared thermometer to control the surface temperature of the glass. The optimal range for softening the adhesive is 80-90 ° C. Exceeding 100 ° C can lead to deformation of the plastic elements of the frame.
Once warmed up enough, the glue becomes viscous, and if you try to remove the lid immediately after heating, it may stick again during the cooling process, so you need to act quickly, but without jerking, insert the suction cup into the bottom of the back cover, closer to the logo, but not at the very edge.
Rear detachment process
Once the suction cup is securely fixed, create a slight tension by slightly pulling the glass upwards. In the resulting microscopic gap in the lower corner, carefully insert a thin metal blade or blade. Your goal is to dissect the adhesive layer, not droop the glass. The movements should be cutting, parallel to the plane of the screen.
Once the blade has entered a depth of 2-3 millimeters, replace it with a plastic mediator. Metal can damage the graphite layer or break the glass from the inside, so we only work with plastic. Slowly drive the mediator along the side edge, making small translational movements. Don't try to go through the entire perimeter at a time; it is better to warm up the phone again if the glue hardens.
⚠️ Note: Do not enter the instrument deeper 3-4 This area contains side button plumes and antenna modules, which will require complex soldering or replacement of plumes.
As you move around the perimeter, you'll hear the characteristic sound of the adhesive coming off. Be very careful at the top of the smartphone, next to the main camera module. Here, the glass can be further fixed, and the risk of damaging the lenses or plumes of the cameras is as high as possible. If the lid does not respond, do not use force - go back to the heating stage.
What to do if the glass cracks when removed?
Disabling plumes and extracting components
When the adhesive layer around the perimeter is cut, the back cover is no longer glued, but it is still connected to the main body by a fingerprint scanner plume (if it is built into the on button) or simply lies on top. In the Redmi Note 9 Pro model, the fingerprint scanner is integrated into the side button, so the plume goes from the side face. However, often the cover can be glued to the display frame, and access to the internal screws is required.
Take care to lift the glass up and put it in a safe place, and you'll have access to a metal screen that covers the motherboard and the battery, and you'll have to unscrew all the visible screws that hold this protective plate to access the connectors. 10-12 They can be different sizes and they can be different lengths.
Once the metal plate is removed, the connectors will be accessed, and the first thing you need to do is turn off the battery, find the battery plume, and carefully disconnect it from the board with a plastic blade, and only after the device is de-energized can the display plumes, cameras, and other modules be turned off, and this will prevent accidental short circuits.
| Component | Location. | Type of attachment | Risks of withdrawal |
|---|---|---|---|
| Battery | Central lower part | Glue tape + connector | Bloating, ignition |
| Main camera. | Upper left corner | Screws + plume | Dust hitting the matrix |
| Charging charges | Lower part of the hull | Screws + plume | Microphone contact break |
| Dynamician | Lower end | Screws + glue frame | Membrane damage |
If your goal was to replace the battery, now that access is open, you can remove the old battery, and it's also planted on glue, so you may need to heat the bottom of the case and use a special hood or suction cup to gently lift the battery.
Cleaning the frames and installing a new cover
Installing a new back cover is impossible without carefully preparing the seat. The old glue must be removed completely, otherwise the new panel will fall unevenly, and dust and moisture will enter the gaps. Use a plastic card or blade to scrape the main residues, and then wipe the frame with a cotton disc dipped in isopropyl alcohol.
After cleaning, degrease the surface. Make sure there are no villi or dust on the frame. Now apply a new layer of glue. For the Xiaomi Redmi Note 9 Pro, it is recommended to use a special glue B-7000 or a pre-cut adhesive, which comes complete with quality copies of the covers.
- 🧹 Carefully remove all remnants of old glue from the metal frame.
- 🧪 Degrease the surface with alcohol for better adhesion.
- 📏 Try on a new cover before applying the glue to make sure the holes match.
- ⏳ Let the glue dry under load during 1-2 hours.
Carefully combine the new lid with the body, starting at the top where the camera is. Make sure the camera block hits its hole. Then press the edges evenly around the perimeter. For better fixation, you can use stationery gums to wrap the phone around the perimeter while the glue is drying.
Typical errors and precautions
Self-repairing is always a risk. One of the most common mistakes is not heating up enough. Users are afraid to overheat the phone and heat it too little, and then force the glass to break it, remember: glass breaks when bending, not when heating, if the temperature is not above a critical 120-150 degrees.
Another common problem is losing screws or getting them tangled up. The screws in Xiaomi smartphones can be only half a millimeter long, but screwing a long screw into a short hole can punch through the motherboard. Keep a detailed record or use a magnetic mat with markup.
⚠️ Warning: Never use superglue (cyanacrylate) to fix the back cover, its vapors settle on cameras and displays, forming a white plaque, and the glue itself becomes brittle and can damage the case on the next disassembly.
And we also have to mention the moisture protection, which is that when you open the body, the factory moisture protection is broken, and even if you stick the lid perfectly, the phone can no longer be guaranteed to withstand water immersion or heavy rain, and you can take care of the device more carefully than you did before the repair.
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The quality of repairs depends 80% on preparation: cleanness of the workplace, the right tools and patience when heating glue, and haste is the main enemy when working with glass.
When you finish the repair, check the functionality of all the functions: the fingerprint scanner, cameras, speakers and proximity sensor. If everything works correctly, you can consider the task done. A properly executed replacement of the cover will not only restore the aesthetic appearance of the phone, but also protect the internal components from dust.