Step-by-step analysis of Xiaomi Redmi 9C NFC: from the cover to the motherboard

Xiaomi Redmi 9C NFC — budget smartphone NFC-It's a module that, despite the affordable price, has a maintainable design, but it takes care to disassemble it, because the plastic body is latched together, and the plumes of the display and battery are fragile. In this article you will find detailed instructions with photos of the stages, a list of necessary tools and critical warnings that will help to avoid typical mistakes during self-repair.

The Redmi 9C NFC (codenamed angelicanfc) looks like the non-NFC version, but it has different antenna layouts, and it affects how the motherboard is retrieved. We've taken all the nuances and put together a guide that's good for both beginners and experienced craftsmen. If you're planning to replace the battery, display, speaker or camera, here's a step-by-step approach to this particular modification.

Preparation for disassembly: tools and security measures

Before you start, make sure you have everything you need, and if you don't have even one tool, you can damage the body or the internal components, and here's the minimum set.

• 🔧 Plastic blades (2-3 pieces, 0.2-0.5 mm thick) - for dissociating the latches of the body.
• 🔨 The screwdriver (PH00 or PH000) — motherboard-mounting screw.
• 🧲 Magnetic mat or container - so as not to lose small screws (there are 12 pieces!).
• 🔥 Dryer or thermo-air station - for softening the battery glue (temperature 60-80)°C).
• 📱 Suction cup for display - will facilitate the separation of the screen from the body.
• 🔋 Multimeter – to check the battery voltage before disconnecting.

Important: Redmi 9C NFC has one feature - its battery is glued not evenly, but with an emphasis on the left side (from the USB-C connector). This means that when you squirt with a blade, you need to start from the right side, otherwise the risk of tearing the display plume increases 3 times.

⚠️ Warning: If you disassemble a phone with a battery that is under 20%, do not charge it during disassembly. Contact areas on the board may be closed off from static electricity, which will cause the power controller to fail. Use isolated tweezers to work with the board.

Removal of the back cover: technique and typical errors

The Redmi 9C NFC is supported by 16 plastic latches that are located around the perimeter, and the main mistake of the beginners is trying to plug the lid from the corner where the USB-C connector is located.

1. Insert a plastic blade into the gap between the lid and the screen to a depth of 2-3 mm.
2. Carefully drive the shoulder blade along the right side until you hear the characteristic clicks (usually 3-4 latches).
3. Repeat the procedure on the left, bottom and top. Don't force it, because if the lid doesn't respond, you've missed the latch.

Once all the latches are snapped, remove the lid by pulling it upwards from the camera. Be careful: under the lid is a fingerprint scanner plume (if it's installed in your modification), which is only 1 cm long, so don't pull the lid sharply.

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If the latches do not respond, heat the body with a hairdryer along the seam (temperature 50 ° C) - the plastic will become more elastic, and the risk of breaking the fasteners will decrease.

Disconnecting the battery and removing the motherboard

When you remove the lid, the first thing you need to do is turn off the battery. In the Redmi 9C NFC, the battery connector is located at the bottom of the board, next to the USB-C port. Use a plastic blade to gently lift the connector up. Don't pull the wires, in this model, they are soldered to the board and can come off!

The following is the procedure:

• 📱 Unscrew 6 screws of attachment of metal plate, covering plumes (screws of different lengths - remember their location!).
• 🔌 Disconnect the plumes in this order: display → sensor → camera → The plume of the display is the widest and most fragile, and the connector is fixed by a latch that you have to open beforehand.
• 🖥️ Carefully lift the motherboard on the right side (on the side of the volume buttons!

⚠️ Attention: At Redmi 9C NFC And underneath the motherboard is a metal pad that acts as a heat sink for the processor, and don't lose it when you build it, because without it, the smartphone will overheat when you're loading it (like playing games or charging it).

Replacement of the battery: nuances and alternative methods

The battery in the Redmi 9C NFC has a capacity of 5000 mAh and is glued to the body with double-sided tape.

1. Heat the body with a hair dryer (60–70°C) for 2-3 minutes to soften the glue.
2. Put a plastic blade on the right side (where there are no plumes).
3. Carefully pull on the black band that's glued to the battery, and if you don't have the tape, use isopropyl alcohol to dissolve the glue.

When you install a new battery, pay attention to the polarity of the contacts. In this model, the battery connector is asymmetrical, so you can't connect the wrong way, but make sure that there's no old glue left under the battery, which can cause the new battery to swell.

Tip: If you do not plan to install a new battery immediately, seal the contacts of the connector on the board with tape to avoid accidental circuit during assembly.

Display module disassembly: when replacement is required

The Redmi 9C NFC display is three layers: a liquid crystal array (LCD), a touch layer and a protective glass. 80 percent of the time, when a phone falls, only the glass is damaged, but replacing only the glass is not economically feasible — it's cheaper to buy the entire module assembled.

• 🖥️ Vertical or horizontal bars on the screen (damaged matrix).
• 👆 "Sensor dead zones (no response to touch).
• 💡 Backlight flashes or is absent (problem with plume or driver).
• 🔥 Rainbow spots under glass (detachment of the polarizer).

To replace the display:

1. Heat the screen with a hair dryer (70–80°C) for 3–5 minutes to soften the adhesive around the perimeter.
2. Use a suction cup to lift the glass. Put a plastic blade in the resulting gap.
3. Carefully drive the blade along the edge, separating the display from the body. Be careful - the plume of the display is located at the bottom!

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If the screen becomes cloudy or bubbles appear when heated, it is a sign of damage to the polarizing layer, in which case the display module should be completely replaced, even if the matrix is intact.

Building a phone: reverse order and testing

The Redmi 9C NFC should be assembled in reverse order, but with a few critical points in mind:

1. Last, start with the display, make sure the connector latches are fixed (clicking should be heard).
2. Screw the screws cross-cross to avoid board skewing. The screws of different lengths - the longest (3.5 mm) goes to the center of the board.
3. You can set the back cover from the button side. The latches should click without effort -- if the lid doesn't go down, check if the plume is hit. NFC-latch-up.

After assembly, be sure to test:

• 📶 Network and Calls (check signal level in Settings) → SIM-maps and mobile networks).
• 🔋 Charging (plug the charger and make sure the indicator is on fire).
• 🎵 Speaker and microphone (record a voice note and listen to it).
• 📷 Cameras (take photos on the main and front camera).

⚠️ Attention: If the phone doesn't turn on after assembly, but when you connect to charging, the indicator shows, the problem may be in the plume of the power button. It often departs when you install the motherboard carelessly. Disassemble the phone and check the locking of the plume.

Frequent problems after disassembly and their solution

Even with a careful disassembly, there can be problems, and here are the most common ones and ways to fix them:

If artifacts appear on the screen (colored dots, stripes) after disassembly, this may indicate damage to the matrix or plume, in which case the only solution is to replace the display module. For the Redmi 9C NFC, the original parts can be found by the articles:

• The display assembly is MB-DPY-009C or MB-DPY-010C (with NFC).
• Battery: MB-BAT-005C (5000 mAh).
• The back cover is MB-BCK-003C (black) or MB-BCK-004C (blue).

FAQ: Answers to Frequent Questions