Xiaomi Redmi 3X has proven to be a reliable budget device, but even the most durable equipment requires maintenance over time. Disassembly of the gadget may be required to replace a broken screen, install a new battery or clean the speakers from dust.
The process of opening the case of this model has its own nuances that distinguish it from more modern devices with non-removable covers. Unlike flagships, here the design is more modular, which makes it easier to access the main nodes, but requires accuracy when working with plastic latches. Before starting work, you need to prepare the workplace to avoid losing small screws and plumes.
In this article, we will take a closer look at each stage of disassembly, with a focus on hidden screws and fragile connectors, what tools will be needed to safely dismantle and how not to damage the fingerprint scanner plume.
Tools and workplace preparation required
A screwdriver is not enough to disassemble the Redmi 3X properly; you will need a specialized toolkit that allows you to work with micro-screws and plastic elements. Lack of suitable equipment often leads to torn screw hats or damage to the body, so you should make sure that everything you need is available in advance.
The main tool will be a set of precision screwdrivers, including cross bits size PH00 and PH000, which are suitable for screws that fix the motherboard and metal plates, and indispensable assistant will be a mediator or plastic blade, which is needed to snap clips without scratching plastic.
- 🛠️ A set of precision screwdrivers (cross and flat)
- 📱 Plastic mediator or screen suction cup
- 🔥 dryer or warmer
- 🧲 Magnetic screw-sorting mat
Special attention is paid to the organization of space. Small parts are easily lost, so it is recommended to use a magnetic mat or container with cells. screws from different parts of the smartphone can differ in length and thread, and their entanglement can damage the motherboard when assembled. The screws of the motherboard mounting longer than the screws of the lower board, they can not be changed in places.
⚠️ Note: The use of metal tools (knives, needles) to open the body is not strictly recommended, since there is a high risk of damaging the plumes or shortening the contacts of the battery.
☑️ Preparation for disassembly
Removal of the back cover and retrieval SIM-map
The first step in any repair is to dismantle the outer shell. In the Redmi 3X, the back cover is made of metal with plastic antenna inserts and is mounted on a combination of screws and plastic latches around the perimeter, and you should only start working after the device is completely turned off.
First, you need to remove the tray for SIM-To do this, use a special paper clip that comes with the kit, or a thin screwdriver sting. After removing the tray, look at the bottom end of the device, and you will see two screws that lock the bottom of the body.
Then you have to unscrew these two screws. Once they're removed, the lid is still tightly attached to the latches. The best way to unplug them is to use a suction cup by attaching it to the bottom of the back panel, and gently pull it up while you're passing the mediator through the junction of the body. If there's no suction cup, you can gently graze the lid with a mediator, moving from bottom to top.
Don't put too much effort into it if the lid doesn't lend itself. Check if all the screws are twisted and warm the edges with a low-temperature dryer for 30-40 seconds. This will soften the glue that can be used for sealing and make it easier to open. The key is not to damage the plume of the fingerprint scanner that connects the lid to the main board.
Dismantling the battery and lower board
When you remove the back cover, you'll see the inside of the smartphone, and the first thing you need to do is turn off the power to avoid short circuits when you're working with other components. The battery in Redmi 3X is fixed by two screws and plugged into the bottom board.
Unscrew the two screws holding the metal battery press plate. Remove the plate and carefully pull the special tongue (if any) or slap the edge of the battery with a plastic blade. Do not use sharp objects to avoid puncturing the lithium polymer cell, which can lead to fire.
Once the battery is turned off, you can go to the bottom board, where the charging connector is located, and it is mounted with several screws and connected to the motherboard with a wide plume. Carefully click the plume connector, putting it on the nail or plastic tool vertically.
- 🔋 Turn off the battery plume first.
- 🔌 Carefully disconnect the tail of the lower board from the motherboard
- 🔩 Unscrew all visible screws of the lower board fastening
- 🧹 Clean the charger from dust when replaced
When you disconnect the connectors, don't pull the wire, just act on the hard part of the connector. If the plume is glued, you can warm it up slightly, but in this model, they usually lie loose in their channels.
⚠️ Warning: The bloated battery must not be pierced or bent, and must be disposed of immediately in a special container for batteries.
How to safely remove the glued battery?
Disassembly of the main board and removal of the display
The Xiaomi Redmi 3X motherboard is the most complex and expensive component of the device, it is closed with a metal screen and protected by several screws, and to access it, you need to dismantle all the interfering elements, including the vibrator and the upper speaker.
First, unscrew the screws that lock the metal frame around the camera and connectors. Remove the frame and disconnect the camera plumes, the display and the touchscreen. These connectors are tightly aligned, so be careful not to damage the neighboring contacts.
Once all the plumes are turned off, twist all the screws around the perimeter of the board. The number can vary, carefully examine the board from all sides. Once the screws are removed, the board should be easily removed from the case. If something holds it, check if you forgot to unscrew the screws under the other elements.
The display module in this model changes with the frame, which simplifies the process. However, if you change only the glass or the matrix separately, you will need to use a separator and a heating plate, which is a task for professional service. For home disassembly, you just need to know that the module is held on a perimeter glue.
When installing a new display, be sure to check its performance before the final sticker. Connect the plumes, turn on the phone and check the sensor, colors and camera performance. This will save time in the event of a marriage.
Comparison of the complexity of repair Redmi 3X and analogues
To understand the complexity of the work ahead, it’s useful to compare the Redmi 3X’s design to other devices, and the smartphone’s modular build makes it relatively easy to maintain compared to monoblock flagships, where battery access is only possible through removing the display.
Below is a table showing the key design differences that affect the complexity of disassembly and repair.
| Parameter | Redmi 3X | Modern flagships | Budget monoblocks |
|---|---|---|---|
| Access to battery | Through the back cover. | Through the screen or glass | Through the back cover. |
| Cover attachment | Screws + latches | Clay. | Latchers |
| Replacement of the charging connector | Separate fee (easy) | Part of the motherboard (complex) | Separate fees |
| Disassembly risk | Medium. | High-pitched | Low. |
As you can see from the table, the Redmi 3X's modular design allows for basic consumables to be replaced without the risk of damaging the display, making it a great model for those who want to learn how to repair smartphones, but having a lot of small screws requires a lot of discipline in sorting them.
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The Redmi 3X modular build allows you to replace the battery or charging connector in 15-20 minutes without special equipment.
Frequent mistakes in self-disassembly
Even experienced craftsmen sometimes make mistakes, let alone beginners, the most common problem is losing screws or putting them in the wrong holes, which can cause a long screw to go right through the board and close the contacts on the back side.
Another common mistake is that the fingerprint scanner plume is damaged, and it's very thin, and it passes through the gap between the frame and the body, and if you sloppyly remove the back cover, it's easy to tear it, and then the scanner will stop working forever.
- ❌ Use of force where heating is needed
- ❌ Ignoring battery shutdown
- ❌ Application of metal tools inside the body
- ❌ Assembly without prior performance check
Also worth mentioning is the glue bug: Many people forget to clean the old glue before installing a new lid or display, which causes a loose fit and dust to get inside the device, and use a special glue B-7000 or double-sided tape for phones.
⚠️ Warning: Never turn on your smartphone if the display plume is connected but the screen is not pressed against the body.
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Use paint tape to fix the screws right on the laptop lid or mat, signing with a marker where they are taken from.
Device assembly and final inspection
The assembly is done in reverse order, but requires even more care. Make sure that all the plumes are snapped to a characteristic click. When laying the plumes, make sure that they are not twisted or stretched, otherwise when closing the case, they may move away.
After you have all the components installed and you've screwed all the screws, don't rush to glue the lid right away, turn the device on and check all the functions: sound, vibration, cameras, Wi-Fi and sensor, if everything works correctly, apply a new layer of glue or put a new tape on the case.
The final step is to clean the body of fingerprints and glue, let the device lie down for 10-15 minutes for initial glue polymerization before active use, and properly assembled Redmi 3X will last for many years.