Modern smartphones like the Xiaomi Redmi 3S often face internal interventions to replace a worn-out battery or recover from a fall. Unlike newer models with non-shatterable cases, this device retains design features that allow relatively safe access to internal components. However, despite the presence of a removable cover, the process requires some skill and understanding of the mechanism of the latch.
Incorrect opening actions can cause plumes to break, cracks in the plastic frame, or even motherboard failure. Owners often underestimate the complexity of the procedure by relying on simplicity of design, leading to unpleasant surprises in the form of disconnected connectors. Careful preparation and knowledge of the sequence of actions is the key to successful repairs without going to the service center.
In this guide, we will take a detailed look at each step of the rear panel dismantling, paying attention to hidden screws and fragile elements. You will learn which tools are really necessary and which can harm the device. The right approach will allow you to replace the battery or clean the speaker, while maintaining the aesthetic appearance and functionality of your gadget.
Tools and workplace preparation required
Before any electronic manipulations are initiated, a comfortable and safe space must be arranged; the work surface must be clean, well-lit and preferably not conduct static electricity; the use of an antistatic mat or simply a wooden table will significantly reduce the risk of chip damage by accidental discharge.
You need a minimal but specific set of tools to disassemble the Redmi 3S properly. Don't try to replace the lid with just a knife or a credit card, as this is almost guaranteed to cause chips and scratches on the sides of the case. Professional approach starts with the right toolkit.
- 🔧 Phillips screwdriver #00 - the main tool for twisting small screws of mounting boards and speakers.
- 🃏 Plastic spatula (poodger) - necessary for careful snapping of clips without damaging the plastic.
- 🌡️ Hair dryer or heating panel – used to soften the glue if the battery is glued to the body.
- 🧲 Magnetic mat or organizer - for sorting screws of different lengths, so as not to confuse them when assembling.
Special attention should be paid to the condition of the battery before work. If the battery is swelled, it should be removed with the utmost care, avoiding punctures. In this case, heating the device is contraindicated, as this can provoke ignition of the electrolyte. Always check the integrity of the batteries visually.
⚠️ Warning: Never use metal objects (needles, scissors) to lid the lid near the plumes. Metal can damage the insulation of wires or shorten the contacts on the board, which will lead to irreversible consequences.
Design features of the Redmi 3S body
Understanding the architecture of the device is half the success of the repair. Xiaomi Redmi 3S is made in an all-metal case with plastic inserts for antennas, making it durable, but difficult to disassemble compared to all-plastic counterparts. The back cover here is not just put on top, but is fixed by a system of internal latches around the perimeter.
Inside the case are the main modules: motherboard, battery, camera module and dynamic speaker, most of which are accessed after the rear panel is removed.
One of the key features of this model is the location of the main display plume, which runs under the protective plate, so you can't just remove the cover to replace the screen, you need to disassemble the internal structure, which distinguishes the procedure of replacing the display from a simple battery replacement.
Why does the body creak when pressed?
The plastic edge, which is visible when the lid is removed, acts as a buffer, takes the main load on the impacts, and protects the display glass from the pressure from the inside, and when it is not neatly opened, this frame breaks first, losing its shock-absorbing properties.
Step-by-step: how to remove the back cover
The dismantling process begins with the device shutdown and retrieval SIM-These are basic security measures that you can short-circuit or programmatic failures if you ignore them, and then you can flip your smartphone down onto a soft surface.
Find a small ledge at the bottom of the back cover, next to the Mi logo. This is where the panel separation process begins. Carefully tuck the edge of the lid with your nail or plastic blade, trying not to put too much effort into it. You should hear the characteristic click of the first latch.
☑️ Checklist before lid removal
Move around the perimeter of the body, sequentially snapping the clips. Don't try to remove the lid from one side completely before you go all over the circuit. Unevenly releasing the latches will prevent the plastic ears of the mount from breaking. The movements should be sliding, not jerky.
- 📍 Start at the bottom corner near the charging connector.
- 📍 Move along the side face to the volume buttons.
- 📍 Walk along the top edge, bypassing the camera.
- 📍 Close the contour at the second side face.
When all the latches are released, the lid will be easily removed. If you feel strong resistance, don't push, check if the edge is still fastened somewhere. Often, the latches sit tighter in the area of the chamber and require more careful handling. Patience is more important than strength.
Access to internal components and screws
Once you remove the decorative lid, you can see the inside of the smartphone, but you can't get to the battery or disconnect the plumes right away, because they're protected by an extra plastic frame that's screwed, and these screws are often hidden under stickers or are of different sizes.
The top, where the camera and flash are, is usually two screws, and the bottom, near the speaker, is a few more. Use a magnetic screwdriver to unscrew them so you don't drop the fixture inside the case. A lost screw can cause rattling when the vibrator is running.
| Location area | Type of screw | Number of | Appointment |
|---|---|---|---|
| Top part (camera) | Short. | 2 pcs. | Fixing the framework of dynamics |
| Lower part (dynamics) | Medium. | 2-3 pcs. | Fixing of the multimedia module |
| Side edges of the frame | Long. | 2 pcs. | Fixing the main fee |
Once you've unscrewed all the visible screws, you need to carefully remove the plastic frame, which also holds onto the latches, but they're more fragile than the outer lid, and you can poke around the perimeter, controlling the force, and underneath the frame, you'll see the battery and connectors leading to the motherboard.
⚠️ Warning: Before disconnecting any plumes, be sure to disconnect the battery connector from the motherboard.Working with the connected battery can short circuit and burn the power controller.
Battery replacement and battery maintenance
In the Redmi 3S, the battery is attached to the body with double-sided tape. Over time, the glue loses its properties, and the battery can start to bulge or, conversely, hang around. To replace, you need to carefully tuck the edge of the battery with a plastic shovel or a special sucker.
Don't use sharp metal tools to extract the battery. A puncture of a lithium-ion cell causes an instant chemical reaction to release heat and smoke. If the battery sits very tight, you can slightly warm the back of the body with a hairdryer to 40-50 degrees, but don't overheat the device.
💡
The new battery is recommended to be charged to 30-40% before installation, which calibrates the controller and prolongs the battery life.
When installing a new battery, make sure that the contact area is clean. If the old glue remains on the case, it should be removed with alcohol or a special liquid.
Once the battery plume is plugged in, don't rush to close the lid, turn on the device and check if the charge is determined, if the touchscreen is working and if the sound is working, and only when you're sure that it's fully functional, you can start the final assembly, and the test run will save you time to re-disassemble.
Assembly of the device and verification of functionality
The assembly is done in reverse order. First, the internal plastic frame is installed and screwed, make sure that all screws are tightly twisted, but without fanaticism, so as not to break the thread in the plastic. Pay special attention to the plume that goes from the board to the lower speaker - it should lie flat, without clatters.
Then you put on the outer back cover. Start fixing from the top corner, gradually pressing the edges around the perimeter until the characteristic clicks. Equal pressure distribution ensures that all latches fall into place. There should be no gaps between the lid and the frame.
- 🔌 Check the charging connector's operation.
- 📞 Make a test call to check the microphone and speaker.
- 📸 Open the camera and check the focus.
- 📶 Make sure you have stable Wi-Fi and mobile network reception.
If you have a backlash or a foreign sound after you build it, it means that some latch didn't get into the groove or the screw didn't get caught correctly, and then you have to repeat the procedure, and the device that's assembled feels monolithic and doesn't make any sounds when you squeeze it in the hand.
💡
The main mistake in assembly is to ignore the position of the plumes, make sure that no wire is pressed with a screw or frame, otherwise it may break when the lid is closed.