Disassembling the Xiaomi Mi 4 is a process that requires not only accuracy, but also an understanding of the internal architecture of the device, which, despite its age, remains popular with enthusiasts. Owners often face the need to replace a worn battery or broken display, and self-repair can save a significant budget. However, before starting to dismantle, you need to understand the risks: inept actions can lead to damage to plumes or cracks on the body.
The device is built in a pattern typical of the flagships of the time, but has its own nuances, such as hidden screws under plugs and specific latches. To successfully complete the operation, you will need a set of precision screwdrivers, a plastic spatula and a suction cup. It is important to prepare a workplace with good lighting, so you do not lose small cogs and see the state of microscopic contacts.
In this guide, we will take a detailed look at each step of dismantling, from removing the back cover to disabling the motherboard.We will focus on safety and proper order of action so that you do not damage fragile components. Follow the instructions carefully, and your Mi 4 will work like new again.
Tools and workplace preparation required
Quality preparation is half the success of any repair. To work with the Xiaomi Mi 4, you will need a specialized tool, since standard household screwdrivers can lick the edges of the screws. The main tool will be a Phillips cross screwdriver #00 or #000, which is ideal for the screws of the case of this smartphone.
Also an indispensable assistant will be a metal or plastic blade to open the case. Plastic is preferable, since it scratches the frame less, but the metal gives more leverage when cracking tight clips. Remember the suction cup, which will help to evenly lift the back cover without putting excessive effort on the glass.
- 🔧 Precision screwdrivers (mandatory Phillips #00)
- 🛠 Plastic blade (mediator) for opening the body
- 🧲 Magnetic mat or organizer for screws
- 🔦 Powerful lamp or table light for lighting small details
Before you start, be sure to turn off the device. Even if the screen is broken and the phone is not responding, press the power button for 10-15 seconds to make sure the circuit is off, a critical step to prevent short circuits from breaking off the plumes.
☑️ Preparation for repairs
Removal of the back cover and dismantling of the frames
The process of disassembling the Xiaomi Mi 4 begins by removing the back panel, which is attached to the plastic latches around the perimeter. Unlike modern monoblocks, here the lid is removable, but the locks hold it quite tightly. Insert the suction cup at the bottom of the back cover, closer to the center, and gently pull up, while introducing the plastic blade into the gap.
Don't put too much effort into one spot, but rather walk around the perimeter with a spatula, sequentially snapping the clips. A characteristic click will signal a successful release of the site. Move slowly so as not to damage the plastic, which may become more fragile over time.
⚠️ Warning: Be extremely careful in the top of the smartphone where the camera is located.Abrupt movement can damage the camera module or tear off the plume if the cover is not fully detached from the internal elements.
Once you remove the lid, you'll see an internal metal frame that covers most of the components, and it's also locked with screws and latches, and you'll carefully unscrew all the visible screws that hold that frame, and you'll repeat the procedure with the blade along the circuit, and now you'll have access to the battery and the main nodes.
Nuances of frame attachment
Disconnecting the battery and removing the motherboard
The most important step is to turn off the power. Find the battery connector on the motherboard. In the Xiaomi Mi 4, it's located at the top of the board and is closed with a metal screen or plastic lining. Gently tuck the connector into a plastic spatula, moving from the bottom up to disconnect it.
Now you can start removing the motherboard, which is held by multiple screws around the perimeter and a screw hidden under the camera or speaker (depending on the revision), and unscrew all the fasteners by remembering their location, as they can be of different lengths.
| Component | Type of attachment | Features of withdrawal |
|---|---|---|
| Maternity fee | Screws + plumes | Requires a shutdown of 3-4 plumes |
| Battery | Adhesive tape | Heat or solvent needed |
| Camera. | Screw + connector | Very fragile module |
After you unscrew the screws, don't pull the board abruptly. First, check if all the plumes are off. Pay special attention to the plume of the display and touchscreen, which are often forgotten to disconnect. Carefully raise the board from one edge, check for no connections, and remove it from the case.
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The main rule when working with the motherboard is never pull on the board itself if you feel resistance. First, check all possible mounting and connection points.
Replacement of the battery and work with the glue layer
In the Xiaomi Mi 4, the battery is attached to double-sided tape, which eventually loses its properties or, conversely, sticks to the dead. To replace the battery, you may need a hairdryer or a special heating plate to soften the glue. Heat the back wall of the case (if the battery is not removed) or the battery itself carefully, without exceeding the temperature of 60-70 degrees.
Use a plastic card or a spatula to fit the edge of the battery. Move the tool parallel to the plane of the body, trying not to punctur the battery's soft shell. If you damage a lithium polymer cell, it may catch fire or swell, so act as delicately as possible.
- 🔥 Heat the case to soften the glue (do not overheat!)
- 🃏 Use a plastic card to separate the battery
- 🧹 Clean the remains of old glue with alcohol before installing a new one
- 🆕 Use a new adhesive base for reliable fixation
Once the old battery is removed, clean the seat of glue residues. This is a great way to do it with isopropyl alcohol, which evaporates quickly and leaves no traces. Install a new battery by pre-applying a layer of special glue or double-sided electronics tape so that it does not hang around inside the case.
⚠️ Warning: Never use metal tools to pick the battery.Puncture of the battery will lead to an instant chemical reaction, the release of caustic smoke and possible fire.
Dismantling of display and touch screen
Replacing the display in the Xiaomi Mi 4 is one of the most difficult operations, because the screen is glued around the perimeter to the frame. If you only have broken glass and the image is intact, replacing the entire module will be a simpler, albeit expensive, solution. First, you need to completely remove the metal frame, which was discussed earlier.
Heat the front panel of the smartphone with a hair dryer. Move a jet of hot air around the perimeter of the screen for 2-3 minutes. This is necessary to soften the adhesive B-7000 or similar composition that fixes the display module. Do not heat the center of the screen for too long so as not to damage the matrix (if it is intact) or polymers.
Using a suction cup and a thin line or a special string instrument, carefully cut the glue around the perimeter. The line allows you to penetrate the adhesive layer without deforming the glass, as a shoulder blade can do. Move slowly, without jerking. After passing the circle, the screen should separate from the frame.
Heating temperature: 80-90°C
Heating time: 2-3 minutes
Tool: Line or string 0.3-0.5 mmWhen you install a new module, make sure to apply a new layer of glue around the perimeter of the frame. Spread it evenly and let it dry for a couple of minutes so that it becomes sticky but not fluid. Match the module with the frame and press it tightly, locking it with rubber harnesses for 30-60 minutes until full polymerization.
Assembly of the device and verification of functionality
The Xiaomi Mi 4 is assembled in reverse order, but requires increased care. Set the motherboard in place, making sure that it lay flat and all the holes under the screws match. Connect all the plumes to a characteristic click - this is a guarantee of reliable contact.
Before you turn all the screws and close the lid, do a primary check. Connect the battery and press the power button. If the screen catches fire, there's a sound and the touchscreen is running, you did it right. Also check the speakers, microphone and vibrator.
- ✅ Verification of OS on and off
- ✅ Touchscreen testing (flick through the menu)
- ✅ Sound and vibration checks
- ✅ Camera test (frontal and main)
If all systems are working correctly, you can lock the metal frame with screws and snap the back cover. Don't forget the screws hidden under plugs or stickers. Screw the screws cross-to-cross to ensure that the parts of the case fit evenly.
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When twisting the screws, don't tug them over.The plastic in older smartphones becomes brittle, and excessive force can lead to cracks around holes or ripped threads.