Disassembling a smartphone is the first and most important step to successfully repairing or replacing worn-out components. Xiaomi Redmi 4, released in 2016, is still popular due to its reliability, but time takes its toll: batteries lose capacity and charging connectors fail. To replace the battery or fix the speaker, you need to know how to properly dismantle the rear panel without damaging fragile plastic or internal plumes.
Many users are afraid to start dismantling on their own, relying on expensive service centers. However, the process of removing the lid on Redmi 4 does not require specialized expensive equipment if you act carefully and consistently. The main difficulty lies in the mounting system: the device does not have screws on the outside, but is supported by a powerful adhesive layer and internal latches. Understanding the design of the case will allow you to avoid cracks on the frame and chips at the corners, which often happens with rough interference.
In this article, we will take a look at the entire dismantling process, from the preparation of the workplace to the final module separation, which tools are really needed and which can be harmful, and we will also focus on the specific nuances of this particular model, such as the location of the fingerprint scanner plume, which often causes failures when disassembled.
Tools and workplace preparation required
Before any electronics manipulation begins, it is critical to prepare a quality workplace, you will need a flat, well-lit surface, preferably with an antistatic coating, although a clean desk without pile is sufficient for home repairs. The absence of dust minimizes the risk of debris getting under the screen or inside the case, which in the future can cause problems with the sensor or buttons.
To work with Xiaomi Redmi 4 you will need a minimal but specific set of tools. Using inappropriate items such as knives or metal blades is strongly discouraged, as they easily damage the paintwork and can short contacts on the board.
- 🔥 Screen suction cup or plastic suction pen is the main tool for creating the initial gap.
- 🔧 Plastic mediators (scapula) - necessary for snapping latches around the perimeter of the body without scratches.
- 🌡️ Hair dryer (construction or household) - required to soften the adhesive layer holding the cover.
- 🧲 Magnetic substrate or container - for sorting small screws, so as not to lose them in the process of work.
Pay special attention to the heating temperature. The glue used by the manufacturer begins to soften at about 80-90 degrees Celsius. Exceeding this threshold can lead to deformation of the plastic frame or damage to internal components such as the battery. Patience in this process is more important than strength: it is better to warm longer at a lower temperature than overheat the device.
⚠️ Note: Before starting the heating, be sure to remove SIM-A left tray can melt or block access to the insides, and heating the memory card is guaranteed to knock it out.
Technology of heating the body and creating a gap
The first step in disassembling Redmi 4 is to heat the perimeter of the back cover, and the adhesive composition that holds the panel solidifies over time, and trying to tear the cover off without first heat treatment will lead to its destruction, and heat should be done evenly, driving a hairdryer around the perimeter of the device, lingering at corners where the adhesive layer is usually thicker.
The heating time depends on the power of your hair dryer and the temperature in the room. Usually the process takes 2 to 4 minutes. You can check readiness by carefully trying to move the suction cup: if it slides easily and the body is warm to the touch (but not burning), then the glue is softened. If you use a building hair dryer, keep it at least 10-15 cm away so as not to melt the plastic.
Once warmed up, place the suction cup at the bottom of the back cover, just above the MI logo but below the camera level. Pull the suction cup up, creating a vacuum, and simultaneously press the opposite side of the case with your thumbs. Your goal is to create a microscopic gap between the frame and the lid, into which you can insert a thin object.
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If the suction cup breaks off, wipe the installation site with alcohol for degreasing or use a drop of water for better grip.
Once there's a minimum gap, immediately insert a plastic mediator or a thin blade (wound with tape) into it. Don't remove the tool immediately, let it become an anchor holding the gap open while you take the second mediator for further work.
Perimeter latching process
Once the initial gap is created, the most important step is to go all the way around the device. The Xiaomi Redmi 4 design involves a lot of plastic latches that hold the lid tightly on the frame, and you should move slowly, starting from where you made the first incision, and gradually moving along the side faces.
Insert the mediator into the gap and lead it along the body, slightly pressing down and inward to cut the glue residue and snap the locks. You will hear the characteristic clicks - this is the normal sound of breaking glue and receding latches. It is important not to immerse the tool too deep, so as not to damage the plumes that may pass close to the edges, or the frame itself.
Be very careful in the top of the smartphone, where the camera and flash are located. In this area, the plastic is often thinner, and the risk of damage to the camera module when pressed inwards by the mediator is very high.
☑️ Checking readiness for withdrawal
When you go around all four sides and the top, the lid should start to detach freely. Don't pull it upwards. First, make sure that no area is stuck. If the lid is sitting tight in some place, go back there with the mediator and walk gently again, perhaps adding a little heat.
Disabling the fingerprint scanner plume
The most critical aspect of the Redmi 4 disassembly is that the lid is separated from the body, and the fact is that on the inside of the back there's a fingerprint scanner module that's connected to the motherboard with a thin, very delicate plume, so if you pull the lid up abruptly, the plume is guaranteed to break and the scanner will stop working.
Once you've snapped all the latches, lift the bottom of the lid slightly to gain visual access to the top end of the device. You need to see where the plume is out of frame and out of the board. You need to be careful to bend the lid, but not more than 15-20 degrees.
To turn off the plume, you need a thin plastic tool or nail. Find a connector on the board (usually covered by metal protection or next to it), gently pull the connector lock up, after which the plume will easily leave the connector, only after that you can completely remove the back cover.
⚠️ Note: The fingerprint scanner plume on Redmi 4 is very short. Don't try to completely flip the lid or put it next to the phone without turning off the plume - this will cause it to rupture.
After you turn off, put the lid in a safe place, with the inside up, so you don't scratch the scanner itself or the camera lens, which is also built into this panel, and now you have access to the battery and the internal components.
Comparison of disassembly methods: heating and chemistry
There are several approaches to removing adhesives in smartphones. For Xiaomi Redmi 4, two methods are most relevant: thermal (heating) and chemical (using solvents), each of which has its own advantages and risks that must be considered before starting work.
The thermal method described above is standard and safest for electronics, if the device is not overheated. The chemical method involves the use of special liquids (for example, high concentration isopropyl alcohol or special solvents of glue) that are introduced into the gap to dissolve the adhesive.
Below is a table comparing these approaches for this model:
| Parameter | Thermal method (Fen) | Chemical method (alcohol/solvent) | Mechanical method (without heating) |
|---|---|---|---|
| Safety for plastics | High (when controlling temperature) | Medium (risk of clouding) | Low (high risk of cracking) |
| Risk for electronics | Medium (overheating) | High (liquid hit) | High (mechanical damage) |
| Difficulty of execution | Low. | High (requires experience) | Very high. |
| Time required | 5-10 minutes | 15-20 minutes (waiting for reaction) | 30+ minutes (high risk) |
As you can see from the table, for a home master, the optimal choice is heating. Chemical methods require high qualification, since getting an aggressive liquid under the display or on the board can instantly disable the smartphone, and mechanical impact without preparation is almost guaranteed to break the case.
Frequent errors and possible problems in removal
Even with instructions, beginners often make mistakes that lead to additional costs. One of the most common problems is trying to remove the lid immediately after a short heating, and the glue in the center and corners can remain hard, leading to breakage of the plastic ears of the mount.
Another mistake is using metal tools (scalpels, scissors) to widen the gap. The metal slips off easily and leaves deep scratches on the Redmi 4 aluminum frame, and can also damage antenna inserts, which will worsen the quality of signal reception in the future. Always use only plastic.
Also, the scanner plume is often forgotten, and users, encouraged by the successful perimeter snapping, suddenly tear the lid off, hear a crack, and realize they forgot to turn off the plume, which leads to the need to buy a new back cover assembled with the scanner, because soldering the module is a complex process.
What to do if the lid is cracked?
Keep static electricity in mind. Although modern smartphones have some protection, dry air and synthetic clothing can create a discharge that can damage sensitive electronics. Touch a grounded metal object before you work, or use an antistatic bracelet.
Assembly and final recommendations
Once you have completed the necessary repair work (replacement of the battery, cleaning the speaker or replacing the connector), the assembly stage begins. Before installing the lid, you need to remove the remnants of the old glue from the frame, this can be done gently scraping it off with a plastic blade or using a soft fabric moistened in isopropyl alcohol.
For a reliable fixation of the lid, it is recommended to use a special glue B-7000 or E-8000, which is designed for electronics. It remains elastic after drying, which will allow in the future to remove the lid again without heating. Apply a thin strip of glue around the perimeter of the frame, avoiding hitting the camera, speaker and connectors.
After applying the glue, press the lid tightly around the perimeter and lock the smartphone with rubber rings or put it under a small load for 1-2 hours until completely dry.Do not turn the device on immediately, let the glue grab and the glue pairs (if any) weather out.
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A high-quality cleaning of the frame from the old glue is the guarantee that the new lid will lie flat and without gaps.
Compliance with these simple rules will allow you to successfully remove and install the lid on the Xiaomi Redmi 4, prolonging the life of your device.