Step-by-step analysis of Xiaomi Redmi Note 7: from the lid to the motherboard

Xiaomi Redmi Note 7

climactic

If you're planning to replace a battery, display or speaker, it's important to understand that the Redmi Note 7 isn't designed to be easy to repair. The manufacturer used high-strength adhesives and thin plumes that are easy to damage if handled carelessly. However, with the right approach and toolkit, disassembly takes no more than 30-40 minutes, even for beginners.

Before you start, answer a key question: Why are you disassembling the device? If the goal is to replace the battery due to bloating, you just need to remove the back cover. To repair the display or the camera, you need to completely disassemble, it depends on the toolkit and the degree of risk. For example, when changing the screen, be sure to turn off the battery first, the display plume is connected to the board and can close if you carelessly handle.

Preparation: security tools and measures

You'll need a dedicated toolkit to disassemble the Redmi Note 7, and don't try to do it at hand, which is almost guaranteed to damage the body or the internal components.

• 🔧 Plastic blades (2-3 pieces) - to separate the cover and plumes. Metal mediators are not suitable!
• 🔨 The screwdriver. PH00 — For the back cover screws. PH0 It's too big and it'll rip the slats.
• 🔥 Dryer or thermo-air station - for softening the glue (temperature 60-80)°C).
• 🧲 Magnetic mat or organizer - to avoid losing screws (there are 15 of them)+ piece!).
• 🔋 Tweezers with curved ends - for neat detachment of plumes.
• 🧴 Isopropyl alcohol (90%+) — glue-cleaner.

Pay special attention to the workplace. A flat table covered with soft cloth (such as microfiber) is ideal to avoid scratching the glass. Turn off your smartphone in advance — if the battery is less than 25% dead, there is a risk of short circuit if the board contacts accidentally close. Also prepare spare screws (article: M1.4×3.0 mm) — they often break when unscrewed.

⚠️ Warning: If your Redmi Note 7 has been in water or been hit hard, disassembly can be dangerous! corrosion on the board or a bloated battery (as seen by the deformation of the cover) require professional repair.

💡

Before disassembling, take a photo of the back cover of the smartphone - screws or sensors may be hidden under the stickers (for example, under it, NFC-antenna).

Removing the back cover: the fight against glue and fragile glass

The Redmi Note 7's back cover is glued around the perimeter and its glass surface is extremely vulnerable to chipping. Start by heating the glue - evenly warm the edges of the body with a hairdryer for 2-3 minutes, holding it at a distance of 5-7 cm. The temperature should be comfortable for the hand (not above 80 ° C), otherwise you risk damaging the battery or display.

Then proceed with the algorithm:

1. Insert the plastic blade into the gap between the lid and the frame (start with the lower left corner where the Type-C connector is located).
2. Carefully drive the blade along the edge, gradually increasing the gap. Don't make any effort -- if the lid doesn't lend itself, warm up the area again.
3. Be especially careful in the area of the fingerprint scanner (upper central part) - its plume is easy to tear off!
4. After separation of the cover do not remove it completely - it is connected to the board with a thin plume of the proximity sensor.

If the lid cracks despite all precautions, don't panic. It can be replaced. ~1 500 ₽), But remember, new lids often come without the glue layer. 3M 9448A (0.25 mm thickness) for fixation.

Disconnecting the battery and removing the motherboard

When you remove the lid, first of all, disconnect the battery.

1. Unscrew 2 screws that fix the metal plate over the battery connector (they are marked with black arrows on the board).
2. Carefully pluck the plate and remove it.
3. Tweezers, grab a black battery connector and pull it up.

Now we can start removing the motherboard, which is mounted on 11 screws of different lengths (see the table below) and a few glues, and it's important to remember the location of each screw, because it's easy to confuse them when you build them, which will damage the board.

After you unscrew the screws, gently tuck the board into a plastic blade, starting at the top edge. Be careful: the main camera, fingerprint scanner and vibrator plumes are under the board. They're easy to damage! If the fee does not lend itself, check if all screws are twisted - often forget about the screw under the sticker. NFC-antennae.

⚠️ Note: The Redmi Note 7 has an eMMC chip that is extremely sensitive to static electricity. Before touching the board, touch a grounded metal object (such as a heating battery) or use an antistatic bracelet.

Replacement of the battery: nuances and risks

The Redmi Note 7 battery (BM47, 4,000 mAh) is glued to the body with high-strength double-sided tape, and it will need to be retrieved:

1. Pick up the battery with a plastic spatula on the side (not from the end!).
2. Slowly pull up, while cutting glue with a thread or a special instrument with a "guitar string".
3. Do not bend the battery – this can lead to an internal short circuit.

When installing a new battery (original article: MBJ406340), use a fresh adhesive layer. The best option is a two-sided Tesa 61395 tape (thickness 0.5 mm). Before gluing, clean the body surface of the old glue with isopropyl alcohol.

If the new battery is not turned on, check:

• 🔌 Correct connection of the connector (it should click with the characteristic sound).
• 🔋 The state of contacts on the board - often they are oxidized (cleaned with a swallow).
• 📱 Settings BIOS (If your smartphone doesn’t respond to charging, try clamping down Power. + Volume Up for 10 seconds).

💡

Never use metal tools to remove the battery, even a small damage to the shell can cause fire. If the battery is swelling, don't try to disassemble it yourself!

Disassembly of the display module: plumes and glue

Redmi Note 7 screen (model) JD9365) It consists of three parts: sensory glass, AMOLED-It will require a complete disassembly of the front panel to replace it. Start by heating the display with a hair dryer (temperature 70).°C) for 3-5 minutes - this will soften the glue around the perimeter.

Then proceed as follows:

1. Insert a plastic blade into the gap between the display and the frame (start with the lower right corner).
2. Slowly drive the blade along the edge, separating the glass. Do not go more than 2 mm deep - plumes pass under the display!
3. After separation of the display gently turn it "face down" and disconnect 3 plumes: 📱 Main display plume (wide, 30 contacts). 👆 Sensor plume (thin, 10 contacts). 🔊 Dynamic/microphone plume (black, 5 contacts).

When assembling a new display, use the original adhesive kit (article: Xiaomi Display Adhesive Set — LOCA-glue, but it requires a UV lamp to polymerize. If the display doesn't respond to touch after you've replaced it, check it:

• Integrity of the sensory plume (often torn when sloppy disconnection).
• Correct connection connectors - they should sit tightly, without distortions.
• Settings in Engineer Mode (enter ##3644633## and check the sensor calibration).

Frequent Mistakes and How to Avoid Them

Even experienced craftsmen make mistakes when disassembling the Redmi Note 7, and here are the most common ones and ways to prevent them:

• 🔧 Thrown screws - use a magnetic screwdriver and don't put too much effort. If the screw "breaks", drop it on it. WD-40 And wait 5 minutes.
• 🔋 Battery plume damage – always turn off the battery first thing, even if you change the speaker.
• 📱 Cracked glass cover - don't heat one area for too long. Use "sliding" movements with a hairdryer.
• 🧲 Lost screws – spread them out on a magnetic mat in order of twisting or photograph their location.
• 🔥 Overheating board - do not use a dryer at maximum power. Optimal: 60-70°C.

If after assembly the smartphone does not turn on, perform diagnostics by steps:

1. Check the battery connection (the connector should sit tight).
2. Make sure all plumes (especially the display and power buttons) are connected.
3. Connect the charger – if the charging indicator is on, the problem is in the board or display.
4. Try running the device in Fastboot Mode (press Power + Volume Down). If there is no reaction, there is likely a power problem.

⚠️ Note: If after replacing the battery, the smartphone turns off at 20-30% charge, the reason is incorrect calibration of the power controller. ADB: adb shell dumpsys battery reset Then fully discharge and charge the device.

Assembly: reverse order and testing

The Redmi Note 7 should be assembled in reverse order, but with a few nuances in mind:

• Before installing the cover, check the operation of all components: 📞 Phone calls and microphone. 📷 Main and front cameras. 🔊 Dynamics (top and bottom). 👆 Sensor and fingerprint scanner.
• Apply a thin layer of thermopaste to the processor (if you removed the radiator).
• Twisting the screws cross-cross to avoid skewed boards.
• For sealing, use water-resistant adhesive B-7000 (applied around the perimeter of the cover).

After assembly, perform the test:

1. Check the Volume, Power buttons, if they fail, the screws in the frame are not tight enough.
2. Run the display test in Engineer Mode (Touch Screen section) – all points should be displayed without skips.
3. Make sure the NFC works (test the payment or tag reading).
4. Check the vibrator motor - if it does not work, most likely the plume is severed.

If after assembly there were extraneous noises (squeaking, crackling), the reason may be:

• A loosely attached lid (repair it).
• Getting dust under the display (blow compressed air).
• Distortion of the metal frame (check the screws).

💡

After replacing the display or battery, be sure to reset your settings via Recovery Mode (Volume Up + Power) to avoid software failures associated with changing the hardware configuration.

FAQ: Answers to Frequent Questions