Broken glass or a broken touchscreen on Xiaomi Redmi 9 is a common problem faced by owners of budget but reliable smartphones. Careful replacement of the display module allows you to return the device to its original appearance and functionality without going to expensive service centers. Self-repair requires care, but it is quite real with a minimum set of tools and understanding the internal structure of the gadget.
In this article, we will discuss the process of replacing the display module in detail, paying special attention to the nuances of turning off the plumes and working with the adhesive base. The display module in this model is a single assembly where the matrix and glass are glued together in the factory, which makes it easier for the master to do the job. It is important to understand that any interference with the design of the device carries risks, so following the instructions is critical to the success of the operation.
Before starting disassembly, you need to make sure that you have all the necessary components and conditions for work. Xiaomi Redmi 9 has a plastic back cover, which greatly facilitates access to the insides compared to glass counterparts.
Preparation of the workplace and tools
To perform a repair, it is not enough to buy a new screen; it requires a properly organized space. The work surface must be clean, well-lit and free of unnecessary objects that can get lost or damage parts. The magnetic mat will be an excellent assistant for sorting screws of different sizes, since the design of the smartphone uses fasteners of different lengths.
The Redmi 9’s display replacement toolkit includes specific items that are impossible or extremely difficult to disassemble without, and the use of inappropriate items such as a knife or pin can damage the plastic elements of the case or, worse, puncture the battery.
- 🛠️ Set of screwdrivers: be sure to have a Phillips #00 cross screwdriver and a flat screwdriver for neat tweaking of plumes.
- 🔥 Dryer or thermophen: necessary to soften the adhesive layer holding the display module in the frame of the housing.
- 💳 Plastic card or mediator: used to safely disconnect components without the risk of short circuit.
- 🧪 Isopropyl alcohol: Helps dissolve the remnants of old glue and degrease surfaces before new gluing.
Special attention should be paid to the heating source. A normal household hair dryer for drying hair may not give enough temperature, so it is better to use a temperature-adjusted building hair dryer or a special heater for phones. The heating temperature of the back cover should not exceed 80-90 degrees Celsius, so as not to damage the plastic elements.
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Use a magnetic mat with markings and take pictures of each stage of disassembly - this will help not get confused during assembly and correctly install screws of different lengths.
Rear cover removal and battery protection
The first step in any Xiaomi Redmi 9 repair is to remove the back panel, which in this model is made of polycarbonate. Despite the fact that the plastic is less fragile than glass, it can also crack when handled carelessly, especially in the corners or around the camera hole.
After heating, insert a suction cup at the bottom of the back cover and pull up slightly to create a gap. Insert a plastic blade or mediator into the resulting gap and run it along the perimeter, cutting the adhesive layer. Don't try to remove the lid with a jerk, as it may be glued to a fingerprint scanner or other elements, although in Redmi 9 the scanner is usually located separately.
⚠️ Attention: It is strictly forbidden to use metal tools to smack the back cover, since one careless movement can damage the tail of the side button or, even worse, pierce the lithium polymer battery, which will lead to its ignition.
Once the lid is successfully removed, you will have access to internal components, including the battery pack and motherboard, and the first step is to disconnect the battery plume from the motherboard to shut down the device and eliminate the risk of short circuits in the process of further operation.
☑️ Safe disassembly of the hull
Removing the frame and disabling the display plumes
The display module in Xiaomi Redmi 9 is not only glued, but also fixed by screws around the perimeter of a metal frame or plastic subframe. You need to twist all visible screws, paying attention to their location, as some can be hidden under stickers or rubber plugs. After removing the fastener, the frame also needs to be carefully separated from the body, heating its edges.
When access to the motherboard is free, you can switch to turning off the display plumes. The main plume and the touchscreen plume (if they are separated structurally) are connected to the board through connectors that require careful handling. Use a plastic blade or nail to lift the connector lock up, and only then pull the plume.
It is important not to damage adjacent components, such as the main camera module or speaker, which may be located in the immediate vicinity. If the plume is glued to the body, it must be carefully warmed with a hairdryer and removed, remembering the path of laying before assembling a new module, so that no clamps arise.
- 🔌 Main plume: transmits the image to the matrix, has a wide contact area and requires special attention when installing.
- 👆 Touchscreen plume: responsible for sensor control, often located near the main connector.
- 🔊 Lower speaker plume: in some versions it can interfere with access to the display and requires temporary shutdown.
What to do if the plume is broken?
Pulping the module and installing a new screen
The most important point is the installation of a new display module in the case of Xiaomi Redmi 9. the old module, as a rule, is supported by double-sided tape or a special glue B-7000. It is necessary to carefully clean the frame of the case of the remnants of old glue, using isopropyl alcohol and plastic scraper, achieving a perfectly smooth surface.
A new layer of glue is applied to the cleaned frame or a double-sided tape is pasted around the perimeter. The B-7000 glue dries about 10-15 minutes before the initial grip, so you will have time to adjust the position of the module. Carefully place the new screen in the frame, making sure that all the holes under the speaker and the camera match, and the plumes are displayed in the right direction.
After the module is positioned, you need to connect the plumes to the motherboard. Make sure the connectors are inserted before clicking and are fixed with clamping slats if they are designed. Do not turn the phone on immediately after you connect, first make sure that all the screws of the frame are twisted and nothing prevents closing.
| Work segment | Time required | Difficulty (1-5) | Risk of error |
|---|---|---|---|
| Removal of the back cover | 5-10 minutes | 2 | Low. |
| Shutting down the plumes | 5 minutes | 3 | Medium. |
| Cleaning the frame of the glue | 15-20 minutes | 2 | Low. |
| Installation and gluing | 20-30 minutes | 4 | High-pitched |
Performance check and assembly
Before you can finally fix the back cover, you need to test the new display. Connect the battery and turn on your smartphone to check the display of the image, the color performance and, most importantly, the response of the touch screen throughout the screen area. Swipe your finger around all corners and center, opening the applications and entering the text.
If the image has defects, such as dead pixels, stripes or uneven backlighting, this may indicate a defect of the new module or poor contact of the plume, in which case the plume must be disconnected, the contacts should be wiped with alcohol and reconnected, making sure that the position is correct.
⚠️ Warning: If you find that the touchscreen is not working correctly or "glutting", check if the plume is not transmitted when assembling the body.
Once you've made sure the system works, you can start the final assembly, apply a new glue or tape to the back cover, press it tightly against the body, and lock the device with rubber harnesses or a load for 1-2 hours before the glue is completely dry, which will ensure tightness and dust protection.
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The final check of all functions of the smartphone before the complete gluing of the case is a mandatory stage that will save you from re-disassembly in the event of a defect in the part.
Calibration of the touch screen and troubleshooting problems
After replacing the screen with Xiaomi Redmi 9, you may need to calibrate the touch layer, especially if there are slight inaccuracies in the positioning of the cursor. The MIUI shell does not have a built-in engineering menu for calibration available to the average user, so you can use special applications from the Play Market or engineering code.
To enter the engineering menu, try entering the code ##6484## in the Phone app. In the CIT menu that opens, select "Touchpanel" and follow the instructions on the screen, drawing lines and points in the specified places, which will help the system re-definite the boundaries of the workspace.
- 📱 Touchscreen Repair app: a popular utility for software calibration of the sensor on Android.
- ⚙️ Engineering menu MIUI: allows you to test not only the touchscreen, but also other sensors of the device.
- 🧹 Contact cleaning: sometimes the problem is solved by simply cleaning the plume contacts with alcohol without software calibration.
If calibration doesn't help and there are "phantom" presses, it may be a problem as the module itself being replaced. Cheap copies of screens often have worse sensitivity and may require more complex adjustment or re-replacement.