How to open Xiaomi Redmi 3S: step-by-step disassembly of the body

Xiaomi Redmi 3S, despite its age, remains a popular device due to its reliability and availability of spare parts. However, time spares lithium-ion batteries, and careless handling often leads to cracks in the display. If your device stopped holding the charge or the screen went out after a fall, the only way out is self-repair.

The process of disassembling this gadget has its own characteristics, which distinguish it from modern models with all-metal cases or glass panels. The design here is made in the form of a sandwich, where a metal frame connects the front panel and the back cover. To successfully carry out work, you will need not only accuracy, but also a specific set of tools that will avoid damage to fragile plumes.

In this guide, we will take a detailed look at how to safely open the case, disconnect components and access the motherboard, and it is important to understand that any interference with the design of the device will void the warranty, if it was still in effect, and require compliance with safety precautions when working with electronics.

Tools and workplace preparation required

Before you start dismantling, you need to organize the right workspace, the surface must be clean, well-lit and preferably not conductive electric current. Using an antistatic mat or just a dry wooden board will help to avoid accidental closure of contacts with static electricity, which is harmful to chips.

The Redmi 3S toolkit is standard for budget smartphones, but it has its own nuances. You do not need complex mechanical devices, but the quality of the tool directly affects the risk of damage to screws and plastic.

• 🔧 Screwdriver kit: a Phillips #00 or #000 cross screwdriver is required, as the screws in this device are very small.
• 🔥 Dryer or thermophen: Necessary to soften the adhesive holding the display module and back cover.
• 💳 Plastic card or mediator: for gently snapping latches without scratching metal.
• 🥢 Suction: Helps lift the screen or cover after heating, creating a gap for the tool.

Special attention should be paid to the condition of the screws. In some Xiaomi instances, the screws can be coated with a special locking varnish. If you feel that the screw is not turning, do not use excessive force to avoid breaking the hat. It is better to carefully warm up the screw area with a hairdryer.

⚠️ Warning: Never use metal blades or knives to open the case in the area of the plumes. One awkward movement can cut the current tracks, after which restoration will become economically impractical.

Removal of the back cover and primary access

The first step is always the extraction. SIM-This is a critical step, because a forgotten tray can block the mechanism or damage the contacts when you try to remove the lid.

The back cover in the Redmi 3S is plastic and is mounted on perimeter latches, as well as on two screws hidden under the plugs or at the bottom (depending on the modification). In most cases, the bottom screws must be twisted out immediately. If there are no screws, the cover is only held on tight clips.

To remove the lid, carefully insert a mediator or plastic card into the junction between the frame and the plastic. Drive the tool along the perimeter, listening to the characteristic clicks of the opening latches. Don't be afraid to exert moderate force, the plastic is quite flexible, but sharp jerks can break the mounts.

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Before removing the lid, take a picture of the location of the screws and plumes, which will help you not to confuse anything when you reassemble, especially if you are doing it for the first time.

Once you take the lid off, you'll see the battery and the lower board, and the main components are now closed by a metal radiator screen that's screwed to the middle frame, and at this point you can see the battery connector, which we'll get to in a little bit.

Dismantling of the battery and lower board

The battery in Xiaomi Redmi 3S is glued to the body quite firmly, but not as strongly as in modern monoblocks. Before any manipulation with the insides, the first thing you need to do is disconnect the battery plume from the motherboard, this is done only after removing the metal screen that covers the connectors.

The sub-board contains a Micro-USB charging connector and a microphone, which is mounted with multiple screws and connected to the main board by a flexible plume that runs through a metallic bezel, and be very careful: this plume is very thin and easily torn when stretched.

You can use a suction cup to extract the battery, or you can gently tuck the edge of the battery with a plastic blade. If the battery is sitting dead, you can use the thread method: you can thread a thin thread (for example, a dental thread) under the battery and saw the adhesive layer with translational movements.

Replacing the battery is the most common cause of disassembly. New batteries for this model are easy to find, and installing them significantly extends the life of the device, the main thing is not to damage the battery with sharp objects, as this can lead to fire.

Removal of the display module and metal frame

To get to the motherboard and the top connectors, you need to remove the display module. In Redmi 3S, the screen is glued to a metal frame around the perimeter, which requires heating the front of the device.

Turn the dryer on to the average temperature and warm the screen evenly for 2-3 minutes. Don't hold the hair dryer at one point for too long so as not to damage the matrix or the glue inside it. Once heated, the suction cup is placed at the bottom of the screen, a gap is created, and a mediator is inserted into it.

You can drive the map along all the faces, gradually unplug the module, and underneath the screen, there's a plume that connects the display and the touchscreen to the board, and it can be glued to the frame, so you need to bend the screen slowly, controlling the tension of the cable.

Once the plume of the display is detached (the connector is usually closed by a metal plate on the screws), the screen can be completely removed. Now the metal frame to which the board is attached is free. However, it is often easier to remove the board itself without separating it from the frame if the goal is to replace the connector or clean.

Working with motherboard and plumes

The motherboard in the Redmi 3S is fixed with multiple screws and covered with a metal screen that also acts as a radiator, and removing this screen opens access to the main connectors: the display, cameras, buttons and the battery itself.

The plumes in this smartphone are connected through ZIF-To turn off, you need to carefully lift a small black or white bar-lock up with your nail or plastic blade. You can not pull the plume itself, it will only come out of the engagement after lifting the retainer.

Cameras (main and front) also connect through these connectors. The main camera in this model is quite large and can be attached to an additional frame or glue. When you remove the camera, watch the lens - dust hitting the matrix will lead to black dots in the photos.

If you change the charging connector, you'll need to solder out the old component and solder the new one using the soldering station and flux, which is an operation for advanced users. If you change the board completely, just transfer the necessary elements (for example, a dynamic speaker, if it's not on the train) from the old board.

Assembly of the device and verification of functionality

The assembly is done in reverse disassembly, but there's an important caveat: before you finally twist all the screws and stick the screen, you need to do an initial check, plug the battery, install the display (you can just hold it with your hand), and try to turn the device on.

Check the touchscreen, the sound in the speaker, the vibration and the charging. If everything is working correctly, you can start fixing. Metal screens should fall into place without gaps, and screws should twist without distortion.

To stick the screen and back cover, use a special glue B-7000 or T-7000. Apply it in a thin strip on the low-fat surface of the frame. Excess glue exposed to the outside is easily removed with a finger or a napkin until they are frozen. Complete polymerization of the glue takes about 2-4 hours, so do not load the smartphone at this time.

⚠️ Warning: Don't tug the screws when assembly.Redmi aluminum frame 3S It has a thread that's easy to rip.

Frequent problems in disassembly and their solution

In the repair process, users often face typical difficulties, such as when the phone is built, it doesn't turn on, most often it means that the battery or display plume is not fully inserted into the connector, disassemble the device and reconnect the cables, making sure the locks are closed.

Another problem is the "dead zones" on the touchscreen after the screen is replaced, which can be caused by a defect of a new part or damage to the plume during installation, and it is also worth checking whether the plume is compressed by a screw or a metal plate.

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Quality workplace preparation and the right tools solve 90% of the problems that arise in the process of disassembling complex electronic devices.

If the phone starts to run out quickly after the battery is replaced, it may not be the battery itself that is the problem, but the power controller on the board or the software failure, which may require calibration of the battery or flashing the device.

Conclusion

Disassembling Xiaomi Redmi 3S is a feasible task for a home craftsman with minimal skills and tools. The design of the device is quite logical, and the availability of spare parts makes repairs economically viable.

The main thing is to take your time and monitor the integrity of the plumes. Carefulness at every stage, from the removal of the back cover to the final check, ensures a successful result and return your gadget to life.