Disassembly of the smartphone Xiaomi Mi 4: detailed instructions for repair with your own hands

The Xiaomi Mi 4, launched in 2014, has become one of the brand’s most popular flagships due to its balanced performance and affordable price. However, even such a reliable device requires repairs over time, from replacing the battery to cleaning the connectors or recovering from a fall. It is more difficult to disassemble the Mi 4 than modern models with a modular design, but with the right approach, even a beginner can do it.

In this article, you will find a step-by-step photo instruction, a list of necessary tools, and unique tips for working with fragile body elements - for example, how to avoid damage to the plume of the fingerprint scanner, which often breaks when you disassemble sloppy, we will also tell you which parts can be replaced yourself, and in which cases it is better to contact the service center.

We warn you right away: Xiaomi Mi 4 has adhesive body and fragile latches, so without experience there is a great risk of damage to plastic mounts or display. If you are not confident in your abilities, trust the repair professionals.

Preparation for disassembly: tools and security measures

Before you start disassembling, make sure you have everything you need. Xiaomi Mi 4 requires carefulness: its body is glued together, and the internal components are sensitive to static electricity.

• 🔧 Plastic blades (2-3 (a) - for separation of the back cover without scratches.
• 🔨 The screwdriver (PH00 or PH0) — screw-hole.
• 🧲 Magnetic mat or container – to avoid losing small details.
• 🔥 Hair dryer or thermoair station - for softening the glue (optional, but recommended).
• 📱 Screen suction cup – will help separate the display module.
• ⚡ Antistatic bracelet – protection against damage to chips by static electricity.

Also, prepare your workspace: it should be well lit, free of dust and moisture; put soft cloth on the table so you don't scratch the glass of your smartphone; if you're taking your phone apart for the first time, take a picture of each step, and it will help you put it back together without any errors.

⚠️ Warning: Do not use metal tools to separate the cover! They can damage antenna lines on the inside of the case, which will lead to communication problems (for example, loss of the network). 4G).

Step 1: Removing the back cover

The back cover of the Mi 4 is glued around the perimeter, so you need to separate it carefully. Start by heating the body with a hair dryer (temperature ~50-60 ° C) for 1-2 minutes. This will soften the glue and reduce the risk of damage to the latches.

1. Place the plastic shoulder blade in the gap between the lid and the case at the 3.5mm connector (top of the phone).
2. Carefully swipe along the side of the lid, separating the lid around the perimeter.
3. When the lid begins to move, put it in the second blade on the opposite side.
4. Remove the lid completely, holding it behind the edges - there may be glued areas inside.

Under the lid, you'll see the battery, the motherboard and the plumes. Don't pull the plumes! They're fragile and can come off the board. If the lid doesn't lend itself, warm the case up again with a hairdryer.

Step 2: Shutting off the battery

Before you continue disassembling, be sure to turn off the battery, which will prevent short circuit and damage to the board. On the Mi 4, the battery is connected via the JST 1.0 connector (white) on the motherboard, to disconnect it:

1. Take a plastic spatula and gently slap the connector on the side.
2. Pull it up perpendicular to the board - don't pull it aside!
3. Make sure the connector contacts are not bent.

If the battery is blown up (as seen by the deformation of the lid), do not try to pierce or bend it - this can lead to fire, in which case it is better to immediately replace the battery with a new one.

Step 3: Removing the motherboard

The Xiaomi Mi 4 motherboard is mounted on 8 screws and several latches. Before you remove it, unplug all the plumes:

• 📞 Display module plume (black connector next to the battery).
• 👆 Fingerprint scanner plume (thin white cable under the board).
• 🔊 Dynamics and microphone plume (small connector at the bottom of the device).

Then unscrew all the screws (they can vary in length — remember where you were!) and gently raise the charge by the edges. Don't pull it sharply: there are antenna wires under the board that can be accidentally torn off.

⚠️ Warning: The Mi 4 board has a Qualcomm Snapdragon 801 chip that is sensitive to overheating.If you use a dryer to soften the adhesive, direct the air flow only to the body, not the board!

Step 4: Replace the battery

Xiaomi Mi 4 battery (3080 mAh) loses capacity over time, and replacing it is one of the most common reasons for disassembly. The new battery must be original or certified (for example, from ZMI or Baseus) to avoid problems with the charging controller.

To remove the old battery:

1. Put a plastic blade on the side (where there are no plumes).
2. Carefully pull upwards, separating the adhesive layer. If the battery does not respond, warm it up with a hair dryer (maximum 60 ° C!).
3. Clean the installation site from glue residues with alcohol or isopropyl alcohol.

When installing a new battery, use double-sided tape or a special glue B-7000. Do not drag the screws of the mounting - this can deform the case.

💡

If the phone doesn't turn on after you replace the battery, check to connect the fingerprint scanner plume, which often unplugs accidentally when you build it.

Step 5: Disassembly of the display module

The Mi 4 display, which is 1920×1080, 5 inches, has three layers: glass, sensor, and matrix. If only glass cracks, you can replace it separately, but if you damage the matrix or sensor, you have to change the entire module.

To separate the display:

1. Warm up the front panel with a hair dryer (temperature ~60 ° C) for 2-3 minutes.
2. Suction suction the glass closer to the bottom (where the Home button).
3. Carefully pull up, simultaneously putting the spatula on the edges.
4. Disconnect the display plume from the board (black connector with a latch).

If the display doesn't separate, don't force it, you can damage the plume or the matrix, you'd better warm up the case again and try again. UV-glue and ultraviolet lamp.

💡

When disassembling the display Xiaomi Mi 4, the main thing is not to damage the plume of the fingerprint scanner, which goes under the Home button.

Common Mistakes and How to Avoid Them

Even experienced craftsmen sometimes make mistakes when disassembling the Mi 4, and here are the most common ones and ways to prevent them:

• 🔋 Battery plume damage – always turn off the battery first thing, even if you’re just cleaning the charging connector.
• 📶 Break antenna wires – do not pull the board up sharply; first make sure that all latches are squeezed out.
• 🔧 Mixed screws – use a magnetic mat or sign screws as you are pulled out.
• 🔥 Overheating boards – do not point the hair dryer at the chips; only heat the case or battery.

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

• Connecting the battery and display plume.
• Integrity of antenna contacts on the cover.
• No short circuit (measure the resistance between + and - batteries with a multimeter).

If you damage the fingerprint scanner plume, it can be replaced, but it’s a time-consuming process – it’s easier to turn off the feature in settings (Settings → Security → Fingerprints).

FAQ: Frequent questions about the dismantling of Xiaomi Mi 4