Disassembly Xiaomi Redmi Note 9: step-by-step instructions

Modern smartphones are becoming more difficult to maintain, and Xiaomi Redmi Note 9 is no exception. The design of the device involves the use of adhesive joints to fix the back cover, which requires the wizard to be more accurate and have a specialized tool. Self-disassembly may be required when a broken display, battery failure or replacement of the charging connector when contacting the service center is impossible or impractical for financial reasons.

Before you start dismantling, you need to understand that any interference with the hardware of the device automatically deprives you of an official warranty. If the phone is still in warranty service, it is better to refrain from acting independently and contact authorized partners of the brand. However, if you are firmly determined to continue, carefully prepare the workplace: it should be well lit and the table is free of unnecessary items, so as not to lose small screws.

The process of opening the case requires patience, especially during the separation of the glass rear panel. The glue used by the manufacturer becomes polymerized over time and becomes very durable, so rush is the main enemy. In this article, we will discuss in detail each step, from tool preparation to final assembly, paying special attention to the nuances of working with fragile components and plumes.

Tools and workplace preparation required

The high-quality disassembly of the smartphone is impossible without the appropriate tools. Using improvised tools such as knives or pins often leads to damage to the internal components or damage to the appearance of the case. To work with the Redmi Note 9, you will need a set of precision screwdrivers, since the screws in modern gadgets have specific hats and a very small size.

Special attention should be paid to tools for working with adhesives. Since the back cover is glued around the perimeter, a heat source is needed to soften the adhesive. A household hair dryer is not suitable here because it is impossible to accurately adjust the temperature, so it is better to use a professional thermophen or, in extreme cases, a heating pad, although this will take longer.

• 🔧 Screwdriver kit: cross (PH000, PH00) flat-to-wall.
• 🔥 Thermophen or heating platform for softening glue.
• 🎴 Plastic mediators, suction cup and thin line or metal string.
• 🧲 Magnetic mat or organizer for sorting screws of different sizes.
• 🧤 Antistatic gloves and tweezers with dielectric tips.

⚠️ Warning: Before starting any work, be sure to turn off the smartphone. Attempting to disassemble the connected device with the battery can lead to a short circuit and failure of the motherboard.

The organization of space is also critical. The screws in the Redmi Note 9 are of different lengths and threads. If you confuse their places when assembled, you can damage the threads in the plastic pillars of the case or, worse, screw through the track on the board.

Removal of the back cover and primary access

The first step in the process of disassembly is the removal. SIM-This should be done immediately, so as not to damage the mechanism when the body is deformed during heating, after removing the tray, you should turn on the thermophene and set the temperature in the range of 80-100 degrees Celsius. Heat should be strictly along the perimeter of the device, avoiding hot air in the central part, where the battery and camera are located.

The heating process takes 2 to 5 minutes depending on the power of the equipment. Periodically check the temperature of the back side with your hand - the glass should become hot, but not burning. Excessive overheating can lead to the delamination of the oleophobic coating or even damage to the display matrix if the heat passes through the body.

After enough warming up, a suction cup is attached to the top of the back cover. Pulling the suction cup up, create a small gap between the glass and the frame. In this gap, a plastic mediator or a safety knife blade is carefully inserted. Then, without removing the tool, you need to guide it along the perimeter, cutting the glue layer. For this purpose, a guitar string or a thin line is also great for this purpose, which is "sawed" glue, keeping the ends stretched.

• 🌡️ Heat the perimeter evenly, lingering at corners where the glue is usually more.
• 🚫 Do not use metal blades deep inside to avoid damaging plumes.
• 👐 Hold the tool parallel to the plane of the smartphone while cutting glue.

When the lid is separated, don't pull it sharply to the side. Inside, there may be thin plumes connecting buttons or sensors to the main board, although in Redmi Note 9, the back cover usually doesn't have its own electronic components. However, caution will not hurt. The removed panel is better immediately put to a safe place away from the edge of the table.

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If there is no thermophen on hand, you can use a dense package filled with hot water (not boiling water), attaching it to the back cover on the back cover. 10-15 It's less efficient, but it's safer for electronics.

Dismantling of the protective plastic panel and battery

Once you take the glass out, you'll see a plastic panel that covers the bulk of the insides of your smartphone, and it's attached to a lot of screws of different calibers, and they can be as many as a dozen, and they're all around the perimeter, and they're also in the center, and it's important to twist them out in sequence and remember the location.

First, you remove the screws hidden under the stickers or plugs, then you unscrew the entire circuit and the center mounts, and then the plastic lid is easily removed, opening up the battery, the main plume and the camera module, and at this point you can see the model markings and the main nodes.

The battery in Xiaomi Redmi Note 9 takes up a significant part of the internal volume and is fixed on two strips of special glue. You can't just pull it out like that, because there is a high risk of damaging the lithium polymer battery shell, which can lead to fire. To safely extract, you need to use plastic cards or special blades, putting the battery on the bottom.

Before you start working with the battery, be sure to disconnect the power plume from the motherboard, this is done after removing the metal screen that covers the connectors. Carefully tuck the connector into a plastic blade. If the battery sits very tightly, you can slightly warm the bottom of the case, but only if you are sure that you will not touch the screen on the front side.

Working with motherboard and plumes

The motherboard in the Redmi Note 9 is located at the top of the case and is closed with an additional metal screen that is also screwed, and removing this screen opens access to the main connectors. Here, accuracy is crucial: the plumes are very thin and break with the slightest careless movement.

The plumes must be turned off by vertically moving the plastic blade, you can't smear them with metal objects or pull on the flexible conductor itself, first the battery plume is turned off (unless it's been done before), then the display, touchscreen and cameras, and only after all communications are turned off can the screws holding the board itself be twisted.

When you remove the board, notice its position relative to the volume and on button connectors. Often the board comes at the edge of the button, and a sharp movement can break the mechanical switch. It's better to remove the board by slightly lifting it on one side and carefully removing it from the engagement.

⚠️ Warning: Trains in modern smartphones are very sensitive to clamps. Even a microscopic crack in the conductor can cause the display or camera to fail. Always check the plumes when buying spare parts.

If your goal was to replace the charging socket, the Redmi Note 9 has it soldered on a separate sub-board, which is at the bottom of the case, and to get to it, you have to take out the battery completely and unstick the protective film at the bottom, and the daughterboard is also screwed and connected to the mother with the main antenna plume.

Replacement of the display and touch screen

Replacing the display module is the most common and difficult procedure to repair. The Xiaomi Redmi Note 9 uses an IPS matrix that comes with or without a frame. If you bought a module with a frame, the task is simple: you just need to transfer all the internal components from the old case to the new one.

If the module is frameless, you need to carefully unstick the old broken screen, to do this, the phone warms up again around the perimeter. The separation of the matrix requires caution, because the glass can crumble. After removing the old module, the frame must be carefully cleaned of glue residues using isopropyl alcohol and a blade.

Installing the new screen starts with checking whether it works, plug the new display plumes into the motherboard without gluing it, and turn on the phone to make sure there are no broken pixels and touchscreens before the final build, and if all is well, apply a new B-7000 glue or use a pre-installed adhesive on the module.

• 🧹 Carefully degrease the frame before sticking the new screen.
• ⏳ Let the glue dry at least. 1-2 hour before turning on the phone.
• 🔌 Check the touchscreen until the body is fully sealed.

When you stick a new module, it's important to spread the pressure evenly throughout the area, you can use rubber harnesses or special clips, but don't overdo it to not squeeze the glue inside the matrix, even fit will ensure the correct operation of the touchscreen and protection from dust.

Assembly of the device and verification of functionality

The final step, assembly, requires the reverse sequence of actions: Set the motherboard, plug all the plumes in the correct order. Make sure each connector snaps to a characteristic, barely audible click. Incorrect connection can result in no image or sound.

Put the battery back in place, making sure it's not bloated and lying flat. Stick it onto fresh double-sided tape. Set a plastic safety panel and twist all the screws. Note that the screws can come in different lengths: longer screws usually twist around corners or in places where heavy elements are attached.

The back cover is glued to a special sealant. Apply a thin layer of B-7000 glue around the frame perimeter or use a ready-made adhesive base. Press the lid and lock the phone with rubber bands for 15-20 minutes. After drying, wipe the case from the residue of glue.

After assembly, you need to conduct a full test of functionality: check the work of cameras, speakers, microphone, vibration, Wi-Fi and cellular communication, pay special attention to the proximity sensor and fingerprint scanner, which is built into the on button.

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Quality assembly is not only about screws that are twisted, but also about proven tightness, and if the phone has moisture protection, it's lost after disassembly, and you have to take that into account when you're in use.