Modern smartphones, including popular models from Xiaomi, are designed with the expectation of monolithic housing, which creates serious difficulties when trying to access internal components. The back panel of the Redmi Note 8 device is made of tempered glass and is attached to a durable layer of glue, not screws, which requires the master to be especially careful and have specific tools. Any careless movement can lead to cracks in the glass or, worse, to damage to the plumes connecting the modules to the motherboard.
The most common disassembly is when you replace a broken glass, battery or charging module, which is located at the bottom of this model. Before starting work, it is important to realize that self-opening the case almost always leads to the loss of the official warranty, if it was still in effect. However, with the right approach and compliance with temperature regimes, replacing the rear cover can be done without fatal consequences for electronics.
In this manual, we will discuss in detail the process of preparing, heating the glue, detaching the panel and subsequent sealing, and will pay special attention to the nuances of working with fragile materials and precautions that beginners ignore. Remember that heating a hair dryer above 90 degrees Celsius can damage OLED-screen or cause battery bloating, so temperature control is a critical success factor.
Tools and workplace preparation required
A high-quality disassembly of a smartphone is impossible without the right set of tools, since the use of improvised tools like knives or pins is guaranteed to lead to damage. You will need a special heating element, whether it is a professional separator, a thermoribbon or, in extreme cases, a household hair dryer, although the latter gives a less controlled result. Also, an indispensable assistant will be a suction cup for lifting glass and a set of plastic mediators that do not scratch the case and do not conduct electricity.
To work with the adhesive layer and then assemble, you must have a B-7000 or E-8000 glue, and isopropyl alcohol to clean the residues of the adhesive. Don't forget to prepare a screw tank and a magnetic mat so that small parts don't get lost in the process. The organization of space directly affects the speed and safety of the operation.
- 🛠️ Heating device: Hair dryer (construction or household at maximum), heatplate or heating pad for the screen.
- 📱 Autopsy tools: Suction, plastic shoulder blades (mediators), metal scalpel (only for initial tweaking).
- 🧪 Expendables: Clay B-7000/T-8000, isopropyl alcohol, lilac-free wipes.
- 🔧 Additional: Tweezers, Torx screwdriver T5 (in case of need to remove internal), container for screws.
⚠️ Warning: Never use superglue (cyanacrylate) to fix the back cover, as its pairs can settle on the camera and speakers, and removing it from the case without damage is almost impossible.
Workplace preparation also includes providing good lighting and no drafts that can cool the heated adhesive at the wrong time.The work surface should be clean, flat and preferably covered with a soft material so that fallen parts do not break.
Safety Techniques and Precautions
Working with electronics and heating devices requires compliance with basic safety rules, neglect of which can lead to injury or damage to property. The first thing you need to completely turn off the smartphone, holding the power button and selecting the appropriate item on the menu, since any manipulation of the device is fraught with short circuit. If the screen is broken and the sensor does not respond, forcibly restart the device or wait for the battery to discharge, but it is strictly forbidden to work with the phone on.
When heating the back cover, it is important not to overheat the adjacent areas, especially in the area where the battery is located directly under the glass. Excessive heating of the lithium polymer battery can cause it to ignite or bloat, which will make further use dangerous. It is recommended to use a thermometer or infrared pyrometer to monitor surface temperature.
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Use nitrile-coated gloves when working with glue and alcohol to protect your hands and avoid fat on your smartphone’s internal components.
Particular care should be taken when working with glass: the fragments of the broken back panel can be very sharp and small. If the cover already has cracks, it is recommended to paste the surface with a wide transparent tape before heating to prevent fragments from spreading throughout the desktop and inside the case.
The process of heating the glue layer
The main step in determining the success of the entire operation is to heat the perimeter of the back cover evenly and adequately. The glue used by the manufacturer softens at a temperature of about 80-90 degrees Celsius, and it takes time to achieve this state.
If you use a dryer, keep it 2-3 cm from the surface and constantly move the hot air flow without lingering long at one point. The whole process of primary heating takes from 3 to 5 minutes, after which you can try to gently tamper with the angle with the mediator. If the tool does not enter or there is strong resistance, the heating must continue, otherwise the glass will burst.
It's important to understand that the thermal conductivity of glass is different from metal or plastic, so the inner surface can be hotter than it looks outside. After the initial heating, let the device lie down for 10-15 seconds so that the heat is evenly distributed over the thickness of the adhesive seam.
How long does it take to heat the lid?
Removal algorithm for the back panel
Once the glue is heated, the most critical mechanical moment comes: insert a thin plastic mediator or scalpel blade (very carefully!) into one of the lower corners where the charging connector usually sits, and slightly twist the tool to create an initial gap. Once the gap appears, lock it with a mediator and start driving the instrument along the side edge, making cutting movements parallel to the plane of the screen.
Move slowly, without trying to pull the lid off by force. Your job is to cut the adhesive layer, not break the glass. Periodically, every 10-15 cm of passing the tool, warm up the area where the mediator tip is again, as the adhesive quickly cools and hardens again. Pay special attention to the area around the main camera module, where the glass can be glued tighter.
☑️ Removal process
When the entire perimeter is passed, the back cover should easily separate from the body.Don't pull sharply, check if any plume is still connected (although in the Redmi Note 8, the plumes usually go from the board to the screen rather than the back cover, but there may be nuances with sensors or antennas in modifications).
Cleaning the frame and preparation for assembly
Before applying a new adhesive, the body frame and the back cover must be thoroughly cleaned of the residues of the old adhesive, which can be done with a plastic blade and a cotton swab dipped in isopropyl alcohol, and the surface must be perfectly smooth and fat-free, otherwise the new layer of adhesive will not provide the necessary tightness and strength.
Carefully inspect the end of the case for microcracks or chips that may have formed during removal. If the frame is deformed, the new lid may not fit in place or will unstuck during operation, and check the status of the battery's downbar and other internal components.
| Cleaning phase | Tool. | Purpose | Importance |
|---|---|---|---|
| Removal of large chunks | Plastic spatula | Removal of the main layer of glue | Tall. |
| Degreasing | Wrapper + alcohol | Fat and dust removal | Critical |
| Finishing polish | Dry napkin. | Pile and moisture removal | Medium |
| Geometry testing | Visually/Finger | Finding the irregularities of the framework | Tall. |
After cleaning, do not touch the fat-free surfaces with your fingers, as the skin fat will worsen adhesion.If you plan to use adhesive tape instead of liquid glue, make sure the factory tape is completely removed and the surface is dry.
Applying glue and final assembly
The Xiaomi Redmi Note 8 is best suited for fixing the back cover with the B-7000 glue or its analogues, as it remains elastic after drying and allows you to open the device if necessary. Apply the glue in a thin continuous strip on the frame of the case, avoiding getting to the camera, speakers and connectors. Extra glue is easily removed in a liquid state, but after drying it is more difficult to remove.
Carefully align the back cover with the body, starting at the top edge (where the camera is), and smoothly press the rest. Make sure the gaps around the perimeter are the same and the cover is flat. After installation, lock the device with money bands or special clips for 15-20 minutes before the initial grasp of the glue.
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Full polymerization of B-7000 glue takes about 24 hours, so on the first day avoid getting moisture, dust and mechanical loads on the smartphone.
⚠️ Warning: Do not turn on the phone immediately after assembly if you accidentally squeeze a lot of glue inside. 10-15 stand off for minutes so that the glue vapors evaporate, and check the touchscreen and sensors.
Once you're fixed, remove the rubber bands and look carefully at the joints. If there's a gap, you can gently press that spot with your finger or add glue with a thin needle. The full strength of the connection will be gained in a day, so on the first day, take care of the phone.