How to carefully remove the back cover Xiaomi Mi 9T: tools, risks and step-by-step analysis

Removal of the back cover Xiaomi Mi 9T — The challenge that owners face when replacing a battery, repairing a camera or a speaker.The model launched in 2019 but is still popular thanks to its retractable front-facing camera and the camera. AMOLED-But the way this smartphone is disassembled is nuanced: the lid is glued around the perimeter, and the inside is covered with fragile plumes.

Many users are afraid to damage the device, and for good reason: if you sloppyly remove the lid, you can tear the plume of the fingerprint scanner or damage the antenna contacts. This guide will help avoid typical errors, find the right tools and perform disassembly with minimal risks. We will consider two methods - using a suction cup and a mediator, and an alternative method for those who do not have specialized tools.

Before you start, evaluate your skills: if you've never taken a smartphone apart, you'd better go to a service center, but if you decide to do it yourself, follow our recommendations and don't miss the preparation steps.

Preparation for disassembly: tools and security measures

You'll need a minimal set of tools to remove the back cover of the Mi 9T, but each one is important. If you don't have one, you can get damaged.

• 🔧 Plastic mediator (or guitar mediator) - to separate the cover and the body!
• 🧲 Suction cup (preferably with metal ring) – helps create an initial effort to detach the lid.
• 🔥 A hair dryer or a thermo-air station is for softening the glue, and even a household hair dryer is fine, but with temperature adjustment.
• 🧴 Isopropyl alcohol (90%+) — cleaning the residue of glue after removing the cover.
• 📦 The screw container - in Mi 9T Different sizes are used, they are easily confused.

Also, prepare the workplace: the desk should be clean, without debris and small parts, it is advisable to use an antistatic mat or at least work on a wooden surface - this will reduce the risk of damage to electronics by static electricity.

⚠️ Warning: Don't use a knife or screwdriver to lid the lid! Metal easily cuts through the plastic and damages the plumes inside. Even a small scratch on the board can lead to a short circuit.

If you don't have a hair dryer, you can try heating the glue with hot water in the bag (the "water bath" method), but this is less effective and fraught with moisture getting inside the device. The optimal temperature for softening the glue is 60-80 ° C. Don't overheat the case: if it becomes hot to the touch, pause.

Method 1: Removal of the lid with a suction cup and a mediator (recommended)

This method is the most secure and suitable for most users. Follow the instructions Step-by-step:

1. Turn off your smartphone and remove it. SIM-The battery should be charged no more than 30%, which will reduce the risk of fire in the event of an accidental short circuit.
2. Heat the back cover with a hair dryer for 2-3 minutes, evenly driving around the perimeter. Pay special attention to the corners - there the glue usually holds stronger.
3. Place the suction cup closer to the bottom edge (where the USB-C connector is located). Press it tightly and pull it upwards, creating a slit.
4. Insert the mediator into the resulting gap and carefully swipe it around the edge, separating the lid. Do not go more than 2-3 mm deep - there are plumes inside!
5. Repeat the heat if the glue is not amenable. After the cover is completely removed, do not remove it sharply, it is connected by a fingerprint scanner plume.

When the lid is separated, carefully disconnect the fingerprint scanner plume (it is attached to the motherboard with a small connector). To do this, apply a plastic blade or tweezers to the lock. Don't pull the plume!

Is the smartphone off?|Whether extracted SIM-map?|Is the perimeter lid heated?|Is the mediator and sucker ready?|Is there a screw container?-->

If the lid does not respond even after heating, do not make excessive efforts. the glue may be too old and dried, in this case, a special solvent for the adhesive (for example, Loctite 731), which is applied to the edge of the lid and aged for 5-10 minutes, will help.

Method 2: Alternative method without suction (for emergency cases)

If you don't have a suction cup, you can do without it, but this method requires more care.

• 📱 Two plastic cards (e.g. bank cards) or thin mediators.
• 🔥 Hair dryer.
• 🧲 Scotch or tape for fixing cards.

Instructions:

1. Heat the cover with a hair dryer, as in the first method.
2. Insert the first card into the gap between the lid and the case at the USB-C connector. Lock it with tape so that it does not fall out.
3. Carefully swipe the second perimeter map, gradually increasing the gap.
4. When the cover is separated by 2/3, remove the fixation of the first card and finalize the mediator.

⚠️ Attention: This method increases the risk of damage to the fingerprint scanner plume, because the control over the force of pressing is lower.

Once the lid is removed, inspect the inside of the lid. The Mi 9T often has fragments of bilateral tape left to be removed with alcohol. Don't use acetone or oil-based solvents: they can damage the plastic!

What is under the cover: the location of components and risks

After removing the lid, you will see the internal structure of the Xiaomi Mi 9T. Here are the key components that can be damaged if you disassemble the sloppy:

Pay special attention to the battery: it is glued to the body and covered with protective film. Never puncture the battery or bend it, it can lead to fire! If your goal is to replace the battery, first disconnect it from the motherboard by turning off the power train (it is under the black safety tape).

Also, look at the metal frame that's mounted with screws, which protects the internal components, but when you reassemble, it's important not to pull the screws over, because it can deform the body.

💡

If you remove the battery replacement cover, take a picture of all the plumes and screws before you turn off, which will help you avoid back-assembly errors.

Common Mistakes and How to Avoid Them

Even experienced craftsmen sometimes make mistakes when disassembling the Mi 9T. Here are the most common of them and ways to prevent them:

• 🔋 The fingerprint scanner plume is damaged when the lid is removed abruptly. Always check if the plume is disconnected before being removed completely.
• 🔥 Overheating of the case - if you heat it too long with a hair dryer, you can melt plastic parts or damage the screen. The optimal heating time is no more than 3 minutes.
• 🛠️ Loss of screws in Mi 9T 3 types of screws are used (length 3 mm, 4 mm and 5 mm). If you confuse them, you risk damaging the board when assembly.
• 💧 Moisture intake - if you use the hot water method, make sure the package is sealed.Even condensate droplets can cause corrosion.

Another common problem is incomplete adhesive separation, and if the lid doesn't move evenly, don't try to pull it off by force. You'd better warm up the problem areas again and repeat the process with the mediator. There are often stories on forums where users have broken the latches of the case in an attempt to save time on heating.

If after the assembly of the smartphone does not turn on, check:

1. Is the battery connected to the motherboard?
2. Is the display plume damaged (it goes along the right side of the device).
3. Whether all screws are twisted - sometimes an unfixed board can close the contacts.

💡

The most common cause of failure after dismantling is a broken plume of the fingerprint scanner. Always unplug it before the lid is completely removed!

Building a device: how to return everything to place

Building Xiaomi Mi 9T after repair is as important as disassembling.

• 🔩 Screw them in reverse order, starting with the longest. Don't pull them over!
• 📱 The plumes -- plug them in neatly, without any inflections. The fingerprint scanner plume should lie flat.
• 🔋 Battery – before connecting, make sure it does not bloat and contacts are clean.
• 🧴 Glue – if you replace the cover, use a new double-sided scotch (for example, 3M 9448A).

After assembly, turn on the smartphone and check:

1. Is the fingerprint scanner working?
2. Is there a network signal and Wi-Fi (antenna check).
3. Does the main and front cameras work?
4. Is the device charging (check the USB-C connector).

If something doesn't work, re-assemble the device and check the plumes, and most often, problems arise from a loosely inserted connector or a compressed cable.

⚠️ Warning: After replacing the battery or cover, the smartphone may display a warning "Unoriginal battery." This is normal for unofficial parts. To remove the message, you need firmware via Fastboot (instructions are on the forum). 4PDA).

When to contact the service center

Despite the detailed instructions, some situations require professional intervention.

• 🔧 You have never taken your smartphone apart and are afraid of damaging your device.
• 💥 The cover cracked when removed, and the cracks are deep (risk of dust/moisture ingress).
• 🔥 Battery swollen or deformed – its replacement requires special precautions.
• 📶 After self-disassembly, the network or Wi-Fi signal was lost (antennas were damaged).

The cost of dismantling in the service varies from 800 to 1500 rubles, depending on the region. Replacing the battery will cost 2000-3,000 rubles (with spare parts), and replacing the lid - 2500-4,000 rubles. Although it is more expensive than self-repair, you get a guarantee for work.

If you do decide to do it yourself, but you're faced with a problem, don't try to force it. For example, if the lid doesn't sit back tight, don't press it -- probably a mislaid plume or a forgotten screw is getting in the way.

💡

Before visiting the service, take a picture of the malfunction (for example, a crack on the lid or a bloated battery) This will help the master to diagnose the problem faster and avoid unfair repairs.

FAQ: Frequent questions about the dismantling of Xiaomi Mi 9T