Disassembly Xiaomi Mi 9T: how to remove the back cover without damage

Why the Mi 9T Removes Caution

The Xiaomi Mi 9T (also known as the Redmi K20 in some regions) is a popular smartphone with a retractable front camera and glass body, and its design, while stylish, makes it difficult to disassemble, with the back cover glued around the perimeter, and fragile plumes and a battery inside that can swell over time. Incorrectly removing the cover often leads to cracks in glass, damage to the fingerprint scanner, or breakage of flexible cables.

This guide will help avoid the typical mistakes, from choosing tools to fixing small parts, and we have taken into account the design features of the Mi 9T, including hidden latches near the volume buttons and the Type-C connector. If you plan to replace the battery, display or clean the cooling system, start with this guide.

⚠️ Critical moment: smartphone has hidden glue under tray SIM-The sloppy compartment of the map that many people miss can damage the antenna contacts.

What tools will you need

For a safe disassembly Xiaomi Mi 9T prepare the following set. Save on tools is not worth it - cheap plastic mediators break and scratch the body:

• 🔧 Screwdriver kit: cross-haired PH00 (for the screws of the body), five-pointed Pentalobe P2 (tray SIM), flat 1.5 mm (for liding).
• 📱 Plastic mediators: 2-3 pieces 0.15-0.2 mm thick (thin - for the first slits, thick - for the separation of the lid).
• 🔥 Hair dryer or thermoplatform: for softening the glue (optimal temperature - 70-80)°C).
• 🧲 Magnetic mat: not to lose screws (in Mi) 9T 12 of them of different lengths!).
• 🛠️ Suction cups: 2 pieces with a diameter of 4-5 cm (for the initial lifting of the cover).
• 🧴 Isopropyl alcohol (90%+): to remove glue residues (do not use acetone!).

💡 Tip: If you don't have a thermoplatform, use a dryer at minimum power, keeping it 10-15 cm from the body. Overheating over 90°C can damage OLED-screen.

Preparing the smartphone for disassembly

Before removing the cover, follow the mandatory steps:

Turn off your smartphone and remove it. SIM-map|Charge the battery to 30-50% (not fully!)|Make a backup copy of the data|Remove the cover and protective film (if any)|Place your phone on a soft surface (such as a napkin)-->

Pay special attention to the battery. If it swells (visible on the raised lid or "slapping" the case when pressed), do not heat the smartphone - it is dangerous! In this case, you should contact the service. Also check if the Fastboot mode is active (the screen should not burn any inscriptions).

⚠️ Note: if you recently updated the firmware, wait 2-3 hours before disassembly. MIUI Block access to connectors with recent updates.

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

Follow the algorithm in strict order, and at each step, check if there are any unseparated glue areas left:

1. Heat the body. Warm up the back cover evenly with a hair dryer for 2-3 minutes, paying attention to the edges. Do not stay in one place for longer than 10 seconds.
2. Separate the lid with suction cups. Stick the suction cups closer to the bottom edge (where the Type-C connector is) and pull up. If the lid doesn't lend itself, repeat heating.
3. Insert the mediator. Insert a plastic mediator into the gap, and carefully guide it around the perimeter, separating the glue. Don't push too hard, there are antenna wires under the lid!
4. Complex areas. The volume buttons and the switch have a lot of glue, so that's where the second mediator or the reheating will help.
5. Final section. When the lid is 70 percent apart, remove the suction cups and rework with the mediator. Don't pull the lid abruptly, it's connected by a fingerprint scanner plume!

📌 Key point: The fingerprint scanner plume is glued to the lid, and it needs to be carefully detached after the lid is completely removed, with a flat screwdriver.

💡

If the lid doesn't lend itself to one of the corners, don't try to pull it off by force. There's probably some unsoftened glue left there. Warm up the area again and try again with the mediator.

Common Mistakes and How to Avoid Them

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

⚠️ Warning: If you find that the battery is swelling after removing the lid (you can see it in the battery bubble), don't continue disassembling. Bloated Li-Pol batteries can ignite if they puncture or deform:

1. Keep the lid back in place (without sticking).
2. Place the smartphone in a non-combustible container (such as a metal tray).
3. Contact the service center for safe disposal.

What to do after removing the cover

When the lid is successfully removed, the inside of the Mi 9T will open up before you.

• 🔋 Battery replacement: unscrew the battery's 4 screws, gently slap it with a plastic blade (not metal!) and unplug the plume. The new battery must be original (BM4B or BM4C for Mi 9T).
• 📸 Camera repair: the main module is mounted on a metal frame, and you need to remove the metal plate to access it (6 screws).
• 🔄 Cleaning the cooling system: remove dust from the graphite pad and copper evaporation chamber tube (do not use wet wipes!).
• 🛠️ Display replacement: requires complete disassembly, including the detachment of the plume of the retractable camera.

💡 Useful tip: if you removed the cleaning cover, check the condition of the thermal paste on the processor. 9T It often dries after 2-3 years, which leads to overheating. Apply a new paste if necessary (Arctic) MX-4 analogue).

💡

After any disassembly, be sure to check the tightness of the body. Xiaomi Mi 9T There is no official protection from water (IP-certificate), but dust and moisture may penetrate through a loosely glued lid.

How to Stick the Cover Back

Reverse assembly is just as important as disassembly. If the lid is not glued properly, it will eventually start to move away and dust will get inside. Use only 3M double-sided tape or the original B-7000 glue (not superglue!).

1. Surface cleaning. Remove the old glue from the lid and body with isopropyl alcohol.
2. For scotch, cut the strips around the perimeter of the lid, leaving holes for the speaker and microphone. For liquid glue, apply a thin layer with a brush without going into the connectors.
3. Keep the lid tight, carefully align the lid with the body, starting at the top (where the retractable camera is) and pressing the perimeter to avoid heavy pressure on the screen.
4. Drying. If you used liquid glue, leave the smartphone under load (1-2 kg) for 4-6 hours.

⚠️ Warning: Do not turn on your smartphone immediately after gluing. Let the glue solidify completely (minimum 2 hours for scotch and 6 hours for scotch). B-7000). Otherwise, the cover may shift, and the retractable camera will jam.

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