How to change the touchscreen on Xiaomi Redmi Note 4X at home

Xiaomi Redmi Note 4X has proven to be a reliable device, but heavy use often leads to mechanical damage to the screen. If the glass is broken, but the image remains clear and the phone responds to touch, it is only a matter of time before cracks begin to interfere with normal operation, in which case the owner faces a choice: carry the device to the service center or try to replace the digitizer yourself.

Self-sensor replacement is a complex but feasible process that requires precision and understanding of electronics. It is important to understand that in this model, the touchscreen (touch panel) and the matrix (display) can be glued together in a factory way, but often you can only replace the top glass with the sensor, retaining the original matrix. In this article, we will discuss in detail how to connect the sensor plume to the connector of the board without skewing to avoid problems with responsiveness after assembly.

Before you start disassembling, you need to evaluate your strength and prepare the workplace. Any dust that gets between the layers of the screen will be noticeable when the backlight is turned on, so cleanliness is the key to success. Next, we will consider the necessary tools and step-by-step algorithm of actions that will help you return the gadget to its original appearance without unnecessary costs.

Tools and workplace preparation required

You can't repair quality without a specialized tool. Using knives or needles instead of professional blades can damage the plastic parts of the case or even puncture the battery, which can cause fire. You'll need a toolkit that provides safe access to the internal components of the Redmi Note 4X.

Special attention should be paid to the heating elements. The glue that holds the module and the frame requires heating to a certain temperature to soften. Insufficient heating will cause the replacement touchscreen to burst when it is removed, but also the surviving matrix, and overheating can deform the plastic elements of the housing or damage the adhesive layer of the oleophobic coating.

• 🔧 Set of screwdrivers (cross-crosses) PH000, PH00 and flat) for twisting screws of different calibers.
• 🔥 A hair dryer or separator to heat the glue (temperature about 80-90 degree).
• 💳 Plastic blades and mediator for neat opening of the body without scratches.
• 🧪 Isopropyl alcohol or special solvent of glue (B-7000) surface-cleaner.
• 🧲 Magnetic mat for sorting screws, as there are many of them in the design and they are of different lengths.

Prepare lighting. Working with small parts requires good visibility so as not to damage fragile plumes, and it is also recommended to remove static electricity from your hands or use an antistatic bracelet, although the risk of static damage to modern smartphones is minimal, it is better to be safe.

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Use a suction cup to initially pull the screen off, but don't pull too hard until the glue warms evenly around the perimeter.

Dismantling of the back cover and internal components

The process of dismantling Xiaomi Redmi Note 4X begins with the removal of the rear metal cover. Unlike many modern monolithic designs, here the lid is removable, but is held on latches and a small amount of glue around the perimeter. Carefully warm up the edges of the rear panel with a hairdryer to ease the adhesion.

Use a thin plastic blade or suction cup to plug the lid in the charging connector or sideways. Move around the perimeter, snapping the locks. Don't use excessive force, the metal may bend, and the lid will not fit tightly back. Once you remove the lid, you will see the battery and the main board closed with a plastic lining.

⚠️ Warning: Before starting work with internal components, be sure to disconnect the battery plume from the motherboard! This will prevent short circuit when the contacts are accidentally touched by the tool.

Then you take the plastic pad that covers the connectors, and it's secured with multiple screws of different sizes, and remember or write down the location of each screw, because screwing a long screw into a short hole can cut through the board. Once you remove the protection, disconnect the display plumes, touchscreen and main camera plume.

Now you can take out the display module itself, along with the frame, which is usually held on two screws at the bottom and adhesive base, and you can carefully pull the module around the perimeter, and if you're planning to change only the glass with the sensor, at this point, the module is removed completely for further operation on the separator or heating platform.

Disassembly of the display module and removal of the old touch screen

This is the most critical stage of repair. If the matrix is intact, your task is to separate the broken glass with the touchscreen from the matrix itself. The factory gluing is very strong, so you need uniform heating. Put the module on the heating platform with the front side up and warm up to a temperature of about 80 degrees for 3-5 minutes.

Use a thin string (nichrome thread) or a special blade-shoulder to separate the layers. The movements should be smooth, sawing, without jerking. The string is wound between the glass and the matrix from any angle where there is a gap. The main danger here is to damage the polarization film on the matrix itself or crush the thin glass of the matrix with the pressure of the tool.

When you separate, you need to constantly inject isopropyl alcohol or solvent into the cut, which helps dissolve the glue and reduces resistance when you move the cutting tool. If you feel that the string is too tight, stop and warm up the module again, and rushing in at this point is guaranteed to lead to the purchase of a new expensive display.

Once the glass is successfully separated, you need to thoroughly clean the surface of the matrix of the glue residues, using a special rubber roller and solvent, and you need to work very carefully, because the matrix is devoid of a protective layer and damaged, and any villi or speck of dust will be visible after assembly.

Installation of a new sensor and assembly of the device

Once the matrix is perfectly cleaned and the new touchscreen (or module assembled) is ready, the assembly process begins. If you've only changed the glass, the new panel should already have a layer of optically transparent adhesive (OCA) applied to it. If not, the adhesive should be applied independently with a separator, avoiding air bubbles.

Combine the new touchscreen with the matrix, controlling the absence of dust between the layers. Carefully press them, starting from the center to the edges, expelling air. After that, the module must be placed under the UV lamp to polymerize the adhesive, if the appropriate type of adhesive was used. The drying time is usually 5-10 minutes depending on the power of the lamp.

Then the module is placed back in the frame, and the frame also needs to be cleaned of old glue and degreased. Apply a new adhesive compound (B-7000 or double-sided tape) around the perimeter of the frame and press the module tightly. Let the glue grab for 15-20 minutes before the final assembly of the case.

• 🔌 Connect the touchscreen plume to the board, making sure of the characteristic snap of the fixator.
• 🔋 Connect the battery and check the sensor before screwing the screws.
• 📱 Install the module in the case, twist the fixing screws.
• 🔒 Close the protection of the board, connect the camera plumes and the display.

The final step is to install the back cover, warm up the edges of the case for better adhesion of the adhesive on the lid, and press it tightly around the perimeter, and make sure that all the latches fall into place with a distinctive sound.

Setting and calibrating the touch panel

After the physical replacement of the touchscreen on the Xiaomi Redmi Note 4X, software calibration may be required. Sometimes the new panel does not work correctly: there are “dead zones”, too high sensitivity or chaotic presses. This is normal for non-original components or simply requires adjustment.

To start, check the normal mode. Swipe your finger around all corners of the screen. If the response is normal, no further adjustment is needed. However, if you notice a shift in touch points, use the engineering menu. To enter it, type ##6484## into the ringer.

In the CIT (Customer Interface Test) menu that opens, select "Touchpanel." Follow the instructions on the screen: you usually need to draw lines or press dots in a certain order, which will allow the system to re-determine the boundaries of the workspace and sensor sensitivity.

⚠️ Warning: Do not use aggressive chemicals (acetone, gasoline) to clean the screen after assembly.They can dissolve fresh glue or damage the oleophobic coating of a new touchscreen.

If the calibration through the engineering menu didn't work, you can try third-party apps from Google Play, like Touchscreen Calibration. They work on a similar principle, but sometimes their algorithms are better at dealing with abnormal sensor behavior. In extreme cases, if the sensor is chaotic, check the density of the plume fit — perhaps the contact broke during the assembly of the case.

Common Errors and How to Resolve Them

Even skilled craftsmen face challenges. One of the common mistakes is not cleaning the matrix properly, and the dust left inside creates air bubbles that can grow over time, and if you see a bubble right after assembly, try to squeeze it gently to the edge, but only if you're confident in the integrity of the layers.

Another common problem is a broken sensor after assembly, often because the touchscreen plume was clamped when a metal shield or plastic lining was installed, and always check the integrity of the plume and the correctness of its stowage in the designated channel before fixing.

And there's also a problem with the proximity sensor, where if you're not tidy, or if you're using a poor-quality glue that's leaked into the top speaker, the sensor can stop properly turning off the screen during a conversation, and you can do that by re-disassembling and cleaning the sensor area with alcohol.

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The quality of the new touchscreen directly affects the life of the repair. Cheap copies can fail in a month, so choose proven suppliers of components.

If the screen starts to turn yellow around the edges or there are iridescent spots, this is a sign of overheating of the matrix during disassembly or mechanical pressure, in which case, unfortunately, only replacing the entire display module at the assembly will help. Careful attitude to temperature and no pressure on the center of the screen is the key to success.