The Xiaomi Redmi Note 4 is a challenge that owners face when replacing a battery, repairing a camera, or cleaning up dust, but the back of the device is not only attached to the latches, but also to the adhesive layer, making it difficult to do so, and the wrong actions can lead to cracks in the case, damage to the plumes, or even failure of the fingerprint sensor.
In this article, you will find a step-by-step guide with photos of key steps, a list of necessary tools and unique tips that are not found in standard guides. We will also analyze typical beginner mistakes and explain how to avoid hidden damage (such as the break of antenna contacts). If you have never taken apart smartphones, this material will help to get everything right the first time.
⚠️ Redmi Note 4 has two modifications – with Qualcomm Snapdragon 625 and MediaTek Helio X20. They are identical on the outside, but the interior layout of the elements may be different. Make sure your model matches the one described in the article (see How to Determine Version»).
Preparation for disassembly: tools and security measures
Before you start removing the lid, make sure to prepare the workplace. The surface of the table should be flat, clean and not slippery — a silicone mat or towel is perfect. Lighting plays a key role: use a desk lamp or a flashlight to see small details.
List of tools that will be needed:
- 🔧 Plastic blade (or mediator) to separate the lid from the body. Metal tools can leave scratches!
- 🔥 Hair dryer (or thermo-air station) - for softening the glue. Optimal temperature: 60-70°C.
- 🧲 Suction cups (2 pcs) - help to evenly pull the lid up. Nipples will suit for removing glasses with a diameter of 30-40 mm.
- 📦 So screw containers, so you don't lose any of the little parts. You can use a magnetic substrate.
- 🧴 Isopropyl alcohol (90%+) — Acetone or solvents should not be used to clean glue residues!
⚠️ Warning: If you're disassembling a smartphone with a faulty battery (blown or leaky), don't use a hair dryer! The risk of lithium-ion batteries catching fire when heated is extremely high.
How to determine the version of Redmi Note 4 (Snapdragon or MediaTek)
The chipset version is not only responsible for performance, but also for the internal layout of the device, for example, in the MediaTek Helio X20 model, the fingerprint scanner plume is located closer to the top of the case, and in the Snapdragon 625, closer to the center, which affects the order of disconnection of the connectors.
You can check the version in two ways:
- Settings: Go to Settings → About Phone → Kernel Version. If you mention msm8953 in the line, you have Snapdragon, if mt6797 is MediaTek.
- By marking on the body: Remove the tray for SIM-The microSD slot will be inscribed over it: SD — Snapdragon; MTK — MediaTek.
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If you bought a smartphone in 2017-2018, you have an 80% chance of having a Snapdragon 625 version.
Step-by-step: Removal of the back cover
Follow this algorithm to minimize the risk of damage, and it takes 15 to 25 minutes depending on the experience.
Turn off your smartphone and remove it. SIM-map|Heat the edge of the body with a hair dryer (30 seconds on each side)|Secure the suction cups on the top and bottom of the lid|Slip the corner near the Type-C connector.
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Step 1. Heat the body.
Turn the dryer on at minimum power and evenly warm up the edges of the smartphone around the perimeter. Keep the hair dryer at a distance of 5-7 cm from the surface so as not to overheat the plastic. Pay special attention to the corners - there is a thicker glue. Sign of readiness: if you swipe your nail along the junction of the cover and the body, you will feel that it is a little "playing".
Step 2. Suction lid separation
Place the suction cups on the top and bottom of the lid (above the camera and below the Redmi logo). Pull up carefully, creating a uniform force. If the lid does not lend itself, do not apply excessive force - better warm up the problem area with a hairdryer again. Once a gap of 1-2 mm appears, insert a plastic blade into it.
Step 3. Perimeter passage
Slowly drive the blade along the edge of the case, separating the latches. Be careful in areas near the volume and power buttons - there are flexible plumes! If you hear a characteristic crunch, stop immediately: it may be a cracked body or a break in contacts.
What to do if the lid does not move?
Common Mistakes and How to Avoid Them
Even experienced craftsmen sometimes make mistakes when disassembling the Redmi Note 4. We have collected TOP-5 errors that lead to breakdowns:
| Mistake. | Effects of consequences | How to avoid |
|---|---|---|
| Use of metal tools | Scratches on the body, damage to antenna lines | Use only plastic or wooden blades |
| Overheating by a hairdryer (>80°C) | Deformation of plastic, detachment of the fingerprint sensor | Control the temperature with a thermometer or tactile (the body should be warm, but not hot) |
| Sharp compartment of the lid | Breakage of the fingerprint scanner plume or vibration motor | Separate the cover slowly, starting at the corner near the Type-C connector |
| Ignoring the screws under SIM-tray | Broken hull latches | Always check for screws with a T3 screwdriver before heating. |
| Cleaning contacts with alcohol without turning off the battery | Short circuit of the fee | Disconnect the battery before any charge manipulation |
⚠️ Warning: If you notice that the fingerprint sensor is not working after removing the lid, do not try to reconnect the plume yourself! 90% of the time, the problem lies in microcracks on the board that require soldering work under the microscope.
What to do after removing the cover: further actions
When the lid is successfully removed, you'll have access to the internal components.
- 🔋 Replacing the battery is the most common cause of disassembly. In the Redmi Note 4, the battery is glued to the battery, so it needs to be carefully tucked in and disconnect the connector.
- 📸 Camera cleanup - dust on the module leads to blurred photos. Use a soft brush and compressed air.
- 🔊 Replacement of speaker or microphone – these elements are mounted on screws and are easily replaced.
- 📡 Check antenna contacts – if the network signal deteriorates, inspect the metal tracks on the lid (they may oxidize).
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Don't touch the board with your bare hands! Static electricity can damage the chips. Use an antistatic bracelet or at least ground by touching a metal object.
If your goal is to replace the display, then after removing the cover you will need:
- Disconnect the battery (disconnect the connector on the board).
- Heat the front panel with a hair dryer (temperature 50°C).
- Carefully tamper with a plastic shoulder blade, starting from the bottom edge.
⚠️ Attention: In Redmi Note 4, the display module is glued to the touchscreen, and if you see slashes or broken pixels after you've been replaced, it means that the plume or matrix has been damaged when you separate, and you'll need to replace the module completely.
How to assemble the smartphone back: tips for sealing
Building a device is as much a process as disassembling it. Here are the key points:
- Cleaning contacts: Before installing the cover, wipe all metal contacts (antennae, charging, buttons) with a cotton swab soaked in isopropyl alcohol.
- Applying glue: Use 3M 9448A double-sided tape (0.25 mm thick) or special adhesive B-7000. Apply it point-by-point around the perimeter, avoiding areas near the speaker and microphone.
- Checking gaps: After assembly, make sure there are no gaps between the lid and the body. If there are any, disassemble the device and reglaciate the lid.
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To check the leakproofness after assembly, place the smartphone in a plastic bag with silica gel for 12 hours. If condensate appears inside the package, the lid is not tightly glued.
If you have replaced the battery, be sure to calibrate it:
- Charge your smartphone to 100%.
- Turn off charging and use the device until full discharge (0%).
- Repeat the charging-discharge cycle 2-3 times.