Step-by-step dismantling of Xiaomi Redmi 3S: tools, schemes and secrets of masters

Xiaomi Redmi 3S is one of the most popular budget smartphones of 2016, which is still used by many users. However, over time, even the most reliable equipment requires repairs: whether it is a battery replacement, dust cleaning or recovery from a fall. If you decide to disassemble the device yourself, this article will help to avoid typical errors and keep the gadget working.

The Redmi 3S has its own nuances: there is no removable back cover, and the body is glued around the perimeter. Without the right tools and knowledge of the sequence of actions, you can damage the plumes, connectors or even the screen. We will take a detailed look at each step from preparing the workplace to assembling back, and also tell you which parts are most vulnerable and how to protect them.

Important: If you've never taken a smartphone apart before, practice on a broken device or watch video instructions before you start. Some steps require jewellery precision!

Preparation for disassembly: tools and safety

Before you start, make sure you have everything you need, and if you don't have even one tool, you can damage the body or the internal components, and here's the minimum set.

• 🔧 Plastic mediators (2-3 - for gently putting the lid on. Metal blades can leave scratches!
• 🔨 Cross screwdriver (size) PH00 or PH0) — A typical screwdriver can rip off the slats.
• 🧲 Magnetic mat or container – so as not to lose small screws (them in Redmi) 3S more than 10!).
• 🔥 Hair dryer or thermo-air station - to soften the glue around the perimeter of the body. The temperature should not exceed 80°C!
• 📸 Smartphone for photo fixation – take each step, so as not to confuse the location of parts during assembly.

Also, prepare the workspace: it should be well lit, draft-free (dust can get inside the case) and with an antistatic coating (for example, a rubber mat). If you work on a desk, cover it with a light cloth, so it will be easier to find a fallen cog.

⚠️ Warning: Do not disassemble your smartphone in humidity above 60% or in a dusty room. Condensation and dust particles can cause contact corrosion or short circuits during subsequent assembly.

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If you don't have a thermophen, you can use a regular hair dryer at a minimum power. Keep it 10-15 cm from the body so that the plastic doesn't overheat.

Step 1: Removing the back cover - how not to break the latches

The most critical thing is that the back panel is separated, and in Redmi 3S, it's glued around the perimeter and it's also latched, and if you pull the lid, you risk tearing the fingerprint scanner plume or tearing off the antenna contacts.

Algorithm of action:

1. Turn off your smartphone and remove it. SIM-cards from the tray (use a paper clip or a special key).
2. Heat the edge of the body with a hair dryer around the perimeter for 1-2 minutes. The glue will become elastic, and the lid will move away more easily.
3. Put a plastic mediator in the gap between the lid and the screen by the headphone jack, carefully guide it along the body, snapping the clamps.
4. When the lid starts to move away, don’t pull it sharply – battery plumes and fingerprint scanners remain underneath!

If the lid doesn't lend itself, warm up the problem areas again. Don't use a knife or metal objects - they'll leave scratches on the aluminum frame.

Heated up the hull around the perimeter |

Plastic mediator is used |

No pressure on the center of the lid (there's a battery!)|

The plumes are not stretched at the separation

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Step 2: Battery shutdown – why it’s critical

Once the lid is removed, the first thing you do is turn off the battery, which is connected through a connector on the motherboard in Redmi 3S, and if you hit the board with a tool on with the battery, you can short-circuit the battery, which will disable the power controller or the processor.

How to turn off the battery safely:

• 🔋 Find the orange battery connector (located at the top of the board, next to the camera).
• 🪛 Carefully tuck it in with a plastic picker or tweezers!
• ⚡ After turning off, check the voltage on the battery contacts with a multimeter - it should be 0 V.

⚠️ Warning: If the battery is swelling (as seen from the deformation of the lid), don't try to remove it yourself! Bloated cells can ignite if punctured.

Step 3: Removing the motherboard - connectors and traps

The motherboard in Redmi 3S is mounted on 11 screws of different lengths, which cannot be confused when assembled, because too long screws can damage the board or screen, and we recommend that you spread them on a magnetic mat in order of extraction or sign them with a marker.

Procedure:

1. Unscrew all screws (use a magnetic tip screwdriver).
2. Unplug the connectors: 📱 Display plume (bottom board, under metal cover). 🔊 Speaker and microphone connector (right of battery). 📷 Main camera plume (top board).

Carefully raise the charge on the right side (there are no plumes there). If it does not go, check if all screws are unscrewed.

Notice the metal screen clips, which can stay on the board or on the screen frame, and don't lose them, or the screen will move away after assembly.

Step 4: Dismantling the screen – when a complete disassembly is required

If you need to replace a display module or touchscreen, you have to completely separate the screen from the frame. In Redmi 3S, it is glued around the perimeter with double-sided tape, and the plumes are additionally fixed with metal clips.

Important points:

• 🔥 Warm up the screen with a hair dryer (temperature) 70-80°C) during 3-5 It'll soften the glue.
• 🧊 After heating, place your smartphone on a cold surface (such as ceramic tiles) for 1 minute – this will create a thermal shock and help separate the screen.
• 🪛 Use a suction cup to lift the screen. Don't pull the glass, just the frame!

If the screen cracks, paste it with tape so the shards don't crumble.The touchscreen and display plumes are very brittle - don't bend them at more than 90 degrees.

Yeah, a few times.|

Yeah, once.|

No, but I want to try |

No, I don't plan on.|

Step 5: Replacing the battery – selecting the part and nuances

Battery at Redmi 3S has a capacity of 4100 mAh (model) BM47). When replacing, it's important to choose a quality counterpart - cheap batteries can swell in a few months.Recommended manufacturers: ZOP, CAMB or the original Xiaomi.

How to Remove Old Battery:

1. Unplug the protective film from the battery (it can stick to the body).
2. Tap the battery with a plastic blade on the side where there are no board elements.
3. If the battery is glued strongly, use isopropyl alcohol - drop a few drops under the battery and wait 2-3 minutes.
4. Don’t use metal tools – they can puncture the battery!

When installing a new battery, make sure that the contacts are not bent and the train is not twisted. After connecting the connector, charge the smartphone 100% and calibrate (discharge to 0% and recharge).

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Never use superglue or heat glue to fix the battery! This disrupts the heat sink and can overheat.

Step 6: Building Back – How to Never Forget a Detail

The Redmi 3S should be assembled in reverse order, but with a few rules in mind:

• 🔍 Before installing the board, check that all metal clips are in place (especially under the screen plume).
• 🔌 Connect connectors to fixing the board with screws - it is more convenient to control the density of the contact.
• 🧹 Remove dust from the speaker and microphone with a soft brush or compressed air spray.

After assembly, turn on the smartphone and check:

• The performance of the fingerprint sensor (if the plume was turned off).
• Sound quality in the speaker and microphone.
• Absence of artifacts on the screen (strips, flickering).
• Battery charging (should go without interruptions).

If something doesn't work, disassemble the device again and check the density of the contacts in the connectors. A common error is a skewed board that causes some connectors to not fully sit down.

Frequent Mistakes and How to Avoid Them

Even experienced craftsmen sometimes make mistakes when disassembling Redmi 3S. Here are the most common of them and ways to prevent them:

If after the assembly of the smartphone does not turn on, check:

• 🔋 Is the battery connector connected (a common mistake is forgetting to plug back in).
• 🔌 Are the contacts bent in the payment connectors.
• 🔧 Whether all screws are twisted (untwisted screws can cause a circuit).

FAQ: Answers to Frequent Questions