We disassemble Xiaomi Redmi 3 correctly: from the lid to the motherboard

Xiaomi Redmi 3 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, from replacing the battery to cleaning connectors or recovering from a fall.

In this article, you will find detailed step-by-step instructions with photos and videos, as well as a list of necessary tools, common beginner errors and safety tips. We will learn how to remove the back cover, disconnect the battery, get to the motherboard without damaging the display module.

Preparation for disassembly: tools and security measures

Before you start dismantling Xiaomi Redmi 3, prepare the workplace and the necessary tools. Work on a clean desk with good lighting - small parts (screws, latches) are easily lost. It is advisable to use an antistatic mat or at least touch grounded metal objects to avoid static discharge, which can damage the motherboard.

Here is the minimum set of tools you will need:

• 🔧 Plastic mediators (2-3 (a) - for the careful liding and disconnection of the plumes.
• ⚙️ Cross screwdriver T4 or T5 for screws of the housing (usually used screws of the type Y000 or JIS).
• 🔋 Screen suction cup – will help to tamper with the display module (optional, but simplifies the process).
• 🧲 Magnetic mat or screw container – to avoid losing small details.
• 📸 Smartphone for photography – fix the location of plumes and screws before disconnecting.
• 🧴 Isopropyl alcohol (90%+) - for cleaning contacts (if required).

If you are planning to replace the battery or clean the connectors, additionally prepare:

• 🔥 Dryer or thermo-air station - for softening the glue under the battery (temperature not higher than 60)°C!).
• 📏 Plastic card or shoulder blade - for careful tweaking of the battery.
• 🛠️ Multimeter – to check the voltage on the battery (should be ~3.7–4.2V).

⚠️ Warning: Don't use metal screwdrivers to tuck in plastic parts, it causes chips and cracks. If you don't have plastic mediators, you can wrap a metal tool with tape.

Step 1: Removing the back cover

The back cover of the Xiaomi Redmi 3 is mounted on the latches and has no screws, but it is not as easy to remove as it may seem. The main difficulty is fragile plastic locks that are easy to break when sloppy dismantling. Start at the bottom edge (on the side of the microUSB connector), where the gap between the cover and the case is slightly wider.

Procedure:

1. Insert a plastic mediator into the gap between the lid and the case at the microUSB connector.
2. Carefully drive the mediator along the edge, alternately clicking the locks.
3. When the lid starts to move away, move to the top edge (from the camera side) and repeat the process.
4. Remove the cover completely, starting at the bottom.

If the lid doesn't lend itself, don't pull it by force - you've probably missed one of the latches. Check if all the latches are snapped, especially in the corners near the antenna lines (they often break when disassembled carelessly).

Step 2: Shutting off the battery

Once you remove the lid, you'll see a battery that's attached to double-sided tape. First rule of safety: before any manipulation of the internal components, be sure to disconnect the battery to avoid short circuits. Redmi 3 requires:

1. Find the battery plume – it is located next to the motherboard and closed with a black insulation tape.
2. Carefully tuck the tape with a nail or plastic mediator.
3. Disconnect the plume connector with the mediator, putting it on the side (do not pull the wires!).

If the battery is blown up (as seen by the deformation of the lid or the battery itself), do not try to pierce or bend it - this can lead to fire, in which case it is better to contact the service center immediately.

⚠️ Warning: If the phone turns on when it's connected to charging after the battery is turned off, it's a sign that the power controller on the motherboard is malfunctioning, and then it's best to stop disassembling and hand it over to a specialist.

To remove the battery completely, it needs to be heated with a hairdryer (temperature not higher than 60 ° C!) for 1-2 minutes to soften the glue. Then gently tuck the battery into a plastic blade, starting at the edge where there is no plume. If the glue is too strong, you can use a thread or guitar string, slicing it under the battery and gradually "cutting" the adhesive layer.

Step 3: Dismantling the motherboard

Once the battery is turned off, you can start removing the motherboard. In Xiaomi Redmi 3, it is mounted on 11 screws of different sizes, so it is important to remember which screw was twisted from where.

Screwing order:

1. Two screws under the battery (near the plume connector).
2. Four screws at the corners of the motherboard.
3. Two screws near the microUSB connector.
4. Three screws next to the camera and speaker.

After unscrewing the screws, gently lift the motherboard with a plastic mediator. It's still connected to the body with several plumes:

• 📱 Display plume (widest, center).
• 🔊 Speaker and microphone plume (thin, right).
• 📷 Main camera plume (short, left).
• 📶 antenna plume (may be glued, disconnect gently!).

Disconnect the plumes one at a time, starting with the display. To do this, apply the black lock of the connector (it opens up) and carefully pull the plume. Don't pull the wires! - enough light press on the base of the plume.

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If the plume doesn't detach, don't force it -- you probably haven't opened the lock until the end. Check if there's an extra latch on the side of the connector.

Step 4: Disassembly of the display module

Xiaomi Redmi 3 display is a glued module that includes a sensor, matrix and metal frame. its replacement requires special care, as if you are not tidy dismantling can damage flexible plumes or break glass.

How to remove the display:

1. Heat the edges of the screen with a hair dryer (50–60°C) for 2-3 minutes to soften the glue.
2. Place the suction cup on the bottom of the screen (where the Home button is located).
3. Carefully pull the suction cup up, while simultaneously putting up the screen with a plastic mediator.
4. Once a gap appears, insert mediators or guitar strings into it to prevent the glue from grasping again.
5. Swipe the mediator around the perimeter, gradually separating the display from the frame.

If the screen is cracked, tape it to keep the fragments from falling apart. Don't push the matrix, it's fragile and can burst with even a little effort. Once you remove the display, you'll see a metal frame that attaches to the body on screws and latches, and you also need to carefully dismantle it to get to the rest of the components (like the Home button or the vibrator motor).

⚠️ Warning: In Redmi 3, the Home button with integrated fingerprint scanner is soldered to the display plume. If you damage it, the touch ID will stop working even after the screen is replaced.

Step 5: Replace components and reverse assembly

If you’ve taken down the Xiaomi Redmi 3 for battery replacement, plug cleaning, or motherboard repair, follow the same steps when you build back, but in reverse order. Here are a few critical points that are often overlooked:

• 🔋 When installing a new battery, make sure that its capacity and model match the original (e.g., BL-416 or BL-417 for Redmi 3).
• 🧲 All screws must be twisted with the same force - pulled screws can damage the board.
• 📶 Check that the antenna contacts on the lid match the contacts on the board – their displacement will lead to a bad signal.
• 🔌 Before final assembly, plug in the battery and check if the phone is switched on (without lid installation).

If you have replaced the display, after assembly, be sure to check:

• 🎨 Color rendering and brightness (no yellowness or broken pixels).
• 👆 Sensor operation (check multi-touch with special applications).
• 🔑 Fingerprint scanner functionality (if it was in the old screen)

If the phone does not turn on after assembly, check:

• Is the battery connected (sometimes the plume is not fully inserted into the connector).
• Are the plumes under the motherboard clogged?
• Are all screws twisted (the absence of even one can cause a circuit).

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The most common build error is forgetting to plug in the speaker plume or the cameras, and the phone turns on but the sound or the main camera doesn't work, and always check the photos taken before the disassembly!

Common Mistakes and How to Avoid Them

Even experienced wizards sometimes make mistakes when disassembling Xiaomi Redmi 3. Here are the TOP-5 problems that users face and how to prevent them:

1. Broken lid latches -- this is caused by trying to remove the lid with the unpatched locks, so you can use two mediators at once, running them parallel to the edges.
2. A damaged display plume -- often tears when the screen is sloppy -- Solution: heat up the glue with a hair dryer and use the guitar strings to separate evenly.
3. Closed motherboard: This happens when you touch contacts or screws with a screwdriver, solution: unscrew the screws last and use an antistatic bracelet.
4. The fingerprint scanner is broken, if you damage the home button plume, solution: don't press the bottom of the screen when you take it off.
5. The bad signal is due to the antenna contacts being misaligned, solution: check their location before closing the lid.

If you do damage a component, don't panic. Many Redmi 3 details can be found on AliExpress or in specialty stores:

• 🔋 Battery - ~500-800 rubles.
• 📱 Display module – ~1 500-2 500 rubles (depending on quality).
• 📷 Camera - ~300-600 rubles.
• 🔊 Dynamics - ~200-400 rubles.

When buying parts, pay attention to compatibility with your Redmi 3 modification (for example, Redmi 3 Pro has other components).

When is the best time to contact the service?

While the Xiaomi Redmi 3 can be disassembled on its own, there are situations where the risk of damaging your phone outweighs the savings.

• 💥 The phone fell into the water - corrosion on the board requires professional cleaning.
• 🔥 The battery is swollen or deformed - replacing it at home is dangerous.
• 🕳️ The board shows burnt-out elements (blackened chips, bloated capacitors).
• 📡 Network signaling or Wi-Fi problems are often associated with damage to antenna tracks.
• 🔧 You need to re-sweeten connectors (e.g. microUSB or charging).

The average cost of a service demolition is between 500 and 1,500 rubles, depending on the complexity of the work, and if you're not confident in your abilities, it's better to pay for professional repairs than risk completely disabling your phone.

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Before you go to the service, back up your data via Mi Cloud or ADB, as some repairs may require a reset.

FAQ: Frequent questions about the dismantling of Xiaomi Redmi 3