Broken glass or a broken sensor on a smartphone is always an unpleasant situation that requires prompt intervention. Xiaomi Redmi Note 4 (including the Note 4X version) has an all-metal body, which makes it much more difficult to access internal components compared to plastic counterparts. Owners often face the dilemma of whether to carry the device to the service center or try to perform repairs yourself, saving a significant amount of money.
In this article, we will discuss in detail the process of replacing the display module, paying special attention to the nuances of disassembling the metal case and working with the adhesive base. Self-repair requires accuracy, the presence of a specialized tool and understanding the risks associated with fragile plumes and batteries. Correctly executed replacement will return the device to the factory appearance and functionality.
Before you start disassembling, you need to make sure that the diagnosis is correct. If there are black spots on the screen, stripes, or the sensor reacts randomly, and the glass cracks, then replacing the module is the only right solution. It is important to understand that in modern smartphones, the glass and matrix are a single indissoluble unit, and their replacement is impossible separately at home without industrial equipment.
Diagnosis of malfunction and selection of components
The first step in any repair is to identify the problem accurately and match the parts. There are several modifications for the Redmi Note 4, and while structurally similar, the connectors or the location of the plumes may differ. The display module for this model consists of a matrix (responsible for the image), a touch screen (touch layer) and a protective glass glued together in the factory.
When choosing a new part in the market, you will encounter three main types of matrixes: IPS, TFT and AMOLED (although AMOLED is extremely rare and often a marketing ploy for this model). The original always has the Mi marking or the matrix manufacturer logo on the plume. Cheap copies can have worse viewing angles, incorrect color reproduction and a less responsive sensor.
- 🔍 Visual inspection: carefully examine the plume of the new module for the ruptures and the quality of soldering of the connector.
- 📏 Size check: the dimensions of the module should perfectly match the frame of the body, without backlashes and gaps.
- 🎨 Color temperature: Include module before final assembly to ensure there is no strong gravitation into blue or yellow.
⚠️ Warning: Buying a bezelless display, you take the risk of damage to the adhesive layer when re-adhesive. For the first time, it is highly recommended to buy a module assembled with a frame, which simplifies installation and guarantees leakproofness.
Also worth paying attention to the presence of oleophobic coating: high-quality copies keep the finger slip, while budget options can feel like “rubber”. Checking through the engineering menu or special applications will help to identify broken pixels that are not visible on the off screen.
Tools and workplace preparation required
The success of the operation to replace the display by 80% depends on preparation. Metal body Redmi Note 4 requires the use of heat to soften the factory adhesive. Without thermal impact, trying to open the back cover will lead to its deformation or destruction, the workplace must be well lit, and the surface is protected from static electricity and loss of small screws.
You'll need a specific set of tools to work with, which is not always included in the standard phone repair kits. Pay special attention to the quality of the suction cup and the mediator, as poor-quality plastic can break inside the case, creating additional difficulties. The use of metal tools inside the case is strictly prohibited because of the risk of short circuit.
☑️ Checklist of instruments
The organization of space is critical. The screws in modern smartphones are of different lengths and threads, if you confuse them, you can damage the board or the case, and it is recommended to use a magnetic mat or a sheet of paper with painted cells, marking the stages of disassembly.
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Use regular white paper to mark the dismantling steps, lay out the screws in order of their removal and sign with a marker (for example, "cover", "board", "screen"), so that there is no confusion during the assembly.
Don't forget to prepare isopropyl alcohol, which is used to degrease surfaces before applying new glue, and helps to gently peel off the remnants of the old adhesive from the frame without damaging the metal.
The process of dismantling the back cover and internal components
The beginning of the disassembly is the most stressful moment. The back cover of the Xiaomi Redmi Note 4 is glued around the perimeter. The heat should be produced evenly, driving a hairdryer around the edges of the device for 2-3 minutes. The temperature should not exceed 80-90 degrees so as not to damage the battery located immediately under the lid.
After heating, the suction cup is placed at the bottom of the lid, closer to the charging socket. Carefully pulling the suction cup, a mediator is inserted into the resulting gap. Movements should be sliding along the edges. Do not try to slap the lid sharply, this will lead to cracks on the metal or glass (depending on the version).
Once the lid is removed, the insides are open, but you can't rush them, so the first thing you need to do is unscrew the screws that hold the battery and the lower board, and they can vary in number, but they're usually located around the perimeter of the lower compartment and above the battery.
| Phase | Action. | Risk | Tool. |
|---|---|---|---|
| 1 | Perimeter heating | Battery overheating | Fen |
| 2 | Post-mortem mediator | Cracking lid. | Suction, mediator. |
| 3 | Removal of the lower plate | Damage to the plume | Torx screwdriver |
| 4 | Shutting down the plumes | Connector break | Plastic spatula |
It is important to turn off the battery plume before any work with other components, which will turn off the device and eliminate the risk of short circuit, the plume is raised neatly with a nail or a plastic blade, you can not pull it.
Removing the old module and installing a new screen
Once the device is de-energized, you can move to disassembling the motherboard and the old screen. In Redmi Note 4, the board is fastened tightly enough and has many screws. You need to unscrew all visible mounts, including those under plastic plugs or stickers.
The display plume and touchscreen are connected to the board through connectors closed by metal clipping slats, these slats are attached by screws of different sizes. Remember or photograph the location of each screw, as they can differ by only 0.5 mm in length, which is critical for the integrity of the board.
Removing the module requires caution. Often there is also adhesive support around the perimeter of the screen. Carefully walk the mediator between the frame and the screen, warming the front part with a hairdryer if the glue is too hard. The new module is installed in reverse order: first, the performance is checked "by weight", then the glue is applied to the frame and the module is pressed.
⚠️ Note: When installing a new module, do not connect the plumes "hot" (with the battery connected). This is guaranteed to disable the power controller or backlights on the motherboard.
Nuances of the glue layer
Make sure the plumes are stacked flat and not clamped by metallic elements of the body. Any sharp angle bend of the plume can cause it to break during operation.
Device assembly and final calibration
Final assembly is a process that requires patience, and once you have a new display and all the plumes connected, you need to attach the motherboard and the protective plates, and the screws are twisted cross-over to distribute the pressure evenly.
Before you finally stick the back cover, make sure you do a test, plug the battery, press the power button, and check the sensor at all corners of the screen, the speaker, the microphone, and the cameras, and if everything is working correctly, you can apply glue to the back cover.
- 🧪 Sensor test: dial ##6484## to log into the engineering menu and select Touchpanel.
- 🔊 Sound check: make sure the speaker is not wheezing and heard clearly.
- 📷 Camera: Take a few photos and check for autofocus.
Use the same B-7000 glue or special adhesive tape to stick the lid, apply the adhesive with a thin layer, press the lid, and lock the device with rubber rings or loads for 30-60 minutes until complete polymerization.
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The quality of repair is determined not only by replacing the screen, but also by restoring the tightness of the case. Poorly glued lid will lead to dust and moisture, which will reduce the life of the device.
Common Errors and How to Resolve Them
Even experienced craftsmen make mistakes, and beginners do more, and one of the most common problems after assembly is a broken touchscreen or dead zones, often due to poor plume contact or connector contamination, just reconnect the plume, before wiping the contacts with alcohol.
Another common mistake is that the plume is damaged when installed, and the thin tracks inside the plume break easily when handled carelessly, and if the screen shows an image but the sensor is not working, it is likely that the touchscreen plume is damaged and the module will have to be changed again.
There's also a problem with the proximity sensor, and if you've changed the screen and stopped dimming during a conversation, check if you've taped a black screen or glue over the sensor area at the top of the module, and in some copies of the screens, the sensor hole may not match the case.