How to disassemble Xiaomi Redmi 9: remove the back cover correctly

Why You Should Remove the Redmi 9 Back Cover

The back cover of the Xiaomi Redmi 9 is not just a decorative element, but protection of the internal components of the smartphone. However, there are situations when it has to be removed, from a banal battery replacement to repairing the camera or speaker. The main problem is that the manufacturer uses glue and latches, which complicates the process of disassembly for an untrained user.

Most often, the cover is removed for:

• 🔋 Battery replacements (if it is swelling or discharged quickly)
• 📸 Repair of the main or front camera
• 🔊 Cleaning or replacing the speaker/microphone
• 📱 Resolving problems with the vibration module
• 🛠️ Diagnostics of the board after falling or getting moisture

It is important to understand that improper disassembly can lead to damage to the plumes, cracks in the lid or even failure of the fingerprint sensor (if it is built into the power button).

Preparation for disassembly: tools and security measures

Before you start removing the lid, prepare the workplace and the necessary tools.

• 🔧 Plastic mediator or shoulder blade (2-3 piece.)
• 🔥 Hair dryer (construction or household with blowing mode)
• 🧲 Screen suction cup (optional but useful)
• 📏 Thin screwdriver (cross or flat)
• 🧴 Isopropyl alcohol (for cleaning glue)
• 📦 Organizer for screws (so as not to lose)

If you don't have specialized tools, you can do with the tools at hand: instead of a mediator, a plastic card will do, and instead of a hair dryer, hot water in a bag (but this is less effective), but remember: using metal objects (knives, screwdrivers) to lick the lid almost always leads to scratches or chips.

⚠️ Warning: If your Redmi 9 was in a damp environment or fell into water, do not heat it with a hair dryer! this can cause corrosion of the board.

Also prepare the working surface:

• 🪑 Use a table with good lighting.
• 🧹 Remove all small items that can get inside the smartphone.
• 📱 Put soft cloth (such as microfiber) under your phone to avoid scratching the screen.

Step-by-step: how to remove the back cover

The process of removing the lid can be divided into three stages: heating the glue, putting on the mediator and neat separation. Let's take each step in detail.

Step 1: Heating the glue layer

The glue that Xiaomi uses to fix the lid becomes elastic when heated to 60-80.°C. For that:

1. Turn the dryer on at average power (temperature ~70°C).
2. Direct the flow of hot air to the edges of the cover, holding the hair dryer at a distance of 5-10 cm.
3. Heat each edge for 1-2 minutes, evenly moving the hair dryer.

If the hair dryer is not available, alternative methods can be used:

• 🔥 Put your phone on a warm battery (not hot!) for 10-15 minutes.
• ☀️ Place the device under an incandescent lamp (60 W) for 5-7 minutes.

Step 2: Filting the cover with a mediator

Once you warm up, take a plastic mediator and start gently pulling the lid on the bottom edge (on the charging connector side), and the adhesive layer is thinner, and the risk of damage is minimal.

Insert the mediator 1-2 mm and slowly lead along the edge, separating the lid from the body. If you feel resistance, do not press harder, but return to the heat of this area with a hairdryer.

⚠️ Attention: There are plumes in the area of the power and volume buttons! Do not insert the mediator deeper than 3-4 mm, otherwise you risk tearing them. If the lid does not respond, check if the latches (usually 4-6 around the perimeter) remain unnoticed).

Step 3: Complete separation of the cover

When the lid split off on 2/3 You can hold it up gently around the perimeter, you can hold it up with your hands, and you can do it smoothly, without jerking -- you can have glued areas inside, and if the lid is stuck to the battery, don't pull it by force, you can put a mediator on it, or you can drop isopropyl alcohol to dissolve the glue.

After removing the cover, you will see the internal structure of Redmi 9.

• 🔋 Battery (stick to the body).
• 📸 Main camera with flexible plume.
• 🔊 Dynamician and microphone.
• 📶 Antenna modules (do not touch them!).

Common Mistakes and How to Avoid Them

Even experienced craftsmen sometimes make mistakes when disassembling the Redmi 9, and here are the most common ones and ways to prevent them:

1. Use of metal tools

Many people try to put a knife or screwdriver on the lid, which results in scratches on an aluminum frame or chipped plastic. Solution: use only plastic or nylon mediators. If you don't have anything at hand, wrap the edge of a metal object with tape.

2. Excessive heating

Overheating with a hair dryer (above 90)°C) can melt plastic latches or damage the battery. Solution: control the temperature with your hand - the body should be hot, but not burning. Optimal use of a heat-controlled dryer.

3. Sharp separation of the cover

If you pull the lid by force, you can tear off the fingerprint sensor plume or damage the antenna contacts, so you can move slowly, 1-2 cm at a time, and when you resist, return to heat.

4. Loss of screws or parts

Redmi 9 uses screws of different sizes (e.g., to attach the motherboard and the camera) and if you mix them up, you can damage the thread. Solution: spread the screws out into individual containers or stick them on tape in order of twisting.

💡

If you find corrosion on the board after removing the lid (green or white), don't turn on the phone! Clean it immediately with alcohol and dry the device for 24 hours.

How to install the cover back: Assembly tips

Replacing the lid back is often more difficult than removing it, and here are some key points to avoid problems:

1. Surface cleaning

Before gluing, remove the residue of old glue from the lid and body of the smartphone.

• 🧴 Isopropyl alcohol (90% and higher).
• 🧼 Cotton swabs or microfibers.
• 🧷 Plastic scraper (for a thick layer of glue).

Do not use acetone or solvents – they can damage plastic!

2. Applying new glue

For reliable fixation of the cover can be used:

• 🎨 Double-sided scotch 3M (thickness 0.2–0.3 mm).
• 💧 Clay. B-7000 (squirt).
• 🔥 Thermoclee (requires heat with a hair dryer after installation).

If you use tape, cut it into strips 3-5 mm wide and stick around the edges of the cover, leaving holes for the speaker and microphone.

3. Checking gaps and buttons

After installing the cover, check:

• 📏 Uniformity of gaps throughout the perimeter (no gaps should be allowed).
• 🔘 The course of the power and volume buttons (they should not be lit).
• 🔊 Speaker and microphone (attach the phone to your ear and check the sound).

⚠️ Warning: If the phone doesn't turn on after assembly, check the battery plume and power buttons are connected. Often they shift when the lid is installed.

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If the lid creaks after installation, it means that the glue is applied unevenly. Take the phone apart and reglue it, paying attention to the corners and edges.

Frequent questions after the Redmi 9 disassembly

Even if you successfully removed and installed the lid, you may have questions about how to proceed.

1.The phone does not turn on after assembly

The reasons may be different:

• 🔌 The battery plume is not connected (check the connector on the motherboard).
• 🔋 Battery discharged (plug charging for 10-15 minutes).
• 💥 Short circuit (if you touched the screwdriver of the board contacts).

If the phone isn’t responding to charging, try connecting it to a PC – it may be identified as an unknown device (this is a sign that the board is alive).

2.The camera or speaker is not working

Most likely, the train has gone or the contacts have been damaged.

• 📸 For the camera: check the connection of the flexible plume to the motherboard (it is under the metal screen).
• 🔊 For the speaker: make sure his contacts are not closed or contaminated.

If the plume is torn, it will have to be replaced (price of a new one). ~300-500 rubles.).

3. buttons are locked or not pressed

This happens when the lid is pressing on the button mechanism.

• 🔧 Carefully bend the metal "tickles" of the buttons (they are located under the plastic keys).
• 📏 Check if the glue interferes with the movement of the buttons.

4. There were creaks when you pressed the lid.

Screams arise from:

• 🧩 Uneven adhesion (glue the lid, paying attention to the corners).
• 🔩 Weakened screws (tighten them up, but do not overdo it).
• 💧 Dust ingress between the lid and the housing (disassemble and clean the surfaces).

Alternative ways to disassemble (if nothing helps)

If the lid does not respond to standard methods, alternative approaches may be tried, but they are more risky and require caution.

Method 1: Use of thread or line

This is a good way to do this if the glue is very strong.

• 🧵 Capron thread or line thickness of 0.3-0.5 mm.
• 🔥 Hair dryer.
• 🧷 Tweezers.

Pull the thread under the lid on the charging connector and carefully saw it with the glue, moving the thread back and forth. Periodically warm the body with a hairdryer.

Method 2: Disassembly through the screen

If the back cover is damaged and it is not sorry, you can go from the opposite:

1. Remove the screen (it is attached to latches and glue, but it is easier to tamper with).
2. Turn off the screen and battery plumes.
3. Get the motherboard - after that the lid will be removed without effort.

This method requires experience, as there is a high risk of damaging the screen plumes.

Method 3: Chemical dissolution of glue

This is a good thing, isopropyl alcohol or white spirit. Apply a few drops along the seam of the lid and wait 5-10 minutes. The glue will soften and the lid will be removed more easily. However, this method is not recommended for phones with damaged waterproofing - the liquid can get on board.

FAQ: Answers to popular questions