How to disassemble <em>Xiaomi Redmi Note 9</em> without damage: detailed guide with photos and videos

Xiaomi Redmi Note 9 (codename Miatoll) remains one of the most popular smartphones in the budget segment even years after its release. Its reliability and maintainability make the device an ideal candidate for do-it-yourself upgrade or repair. However, disassembling this device is fraught with several pitfalls: from fragile cables to unobvious latches that can be broken if handled carelessly.

In this guide we will go through the disassembly process in detail. Redmi Note 9 - from removing the back cover to removing the motherboard. You will learn what tools are needed, how to avoid common mistakes (for example, damage FPC cable for fingerprint scanner), and which spare parts most often fail. We will pay special attention unique feature of this model: double-sided tape under the battery, which, if heated incorrectly, can melt and damage the contacts.

Preparing for Disassembly: Tools and Safety Precautions

Before you begin, make sure you have everything you need. Disassembly Redmi Note 9 requires precision - improvised means like a knife or credit card will not work here. Here is the minimum set of tools:

• 🔧 Plastic picks (0.2–0.4 mm thick) - for separating the case without scratches.
• 🔥 Hair dryer or hot air station (temperature 60–80°C) - to soften the glue under the back cover.
• ⚡ Sucker (diameter 3–5 cm) - helps to lift the lid after heating.
• 🛠️ Screwdriver set: cross PH00, flat 1.5 mm, and five-ray Y00 for the screws under the SIM tray.
• 🧲 Magnetic mat or a container - so as not to lose small screws (there are 15+ of them here!).

Important: Redmi Note 9 has IP53 certification from splashes, so under the back cover you will find rubber gaskets. When disassembling, they are easy to damage - carefully remove the cover so as not to tear the seals along the volume and power buttons. If you plan to put your phone back together, take a photo of the location of all gaskets before the start of work.

⚠️ Attention: Do not use metal tools to separate the housing! Housing Redmi Note 9 Made of polycarbonate, which is easy to scratch. Even minor damage can break the seal and allow dust to get inside.

Removing the back cover: step-by-step instructions with photos

Back cover Redmi Note 9 attached with glue and latches. The main difficulty is not to overheat the case, otherwise the glue will become liquid and flow inside, contaminating the contacts. Follow this algorithm:

1. Turn off your phone and remove the SIM card tray (use a paper clip or a special key).
2. Heat the edges of the case hairdryer for 2-3 minutes, holding it at a distance of 5-7 cm. Temperature - no higher than 80°C!
3. Use a suction cup to lift the lid at the charging connector (there are fewer latches there). Insert the pick into the gap created.
4. Guide the pick carefully along the body, separating the latches. Apply more force at the corners - the glue is applied thicker there.

If the lid does not budge, don't pull it by force - most likely you missed the latch. Return to heat for another 1-2 minutes. Typical places where latches break during careless removal:

• 📍 Around the camera (especially the top left corner).
• 📍 Bottom part - 近 connector USB-C.
• 📍 At the volume buttons (there is a trail of side keys).

After removing the cover, you will see the battery covered with black film. Don't take it off right away - contacts are hidden under it NFC antennas, which are easy to damage. Also note orange seal around the power button - you need to carefully separate it and save it for reassembly.

Disconnecting the battery and removing the motherboard

Before touching the components, be sure to disconnect the battery. B Redmi Note 9 this is done by disconnecting FPC connector (white) on the motherboard. Use a plastic pick to gently pry up the latch:

1. Найдите белый разъём с надписью "BATTERY" рядом с верхним краем платы.
2. Вставьте медиатор под чёрную защёлку и слегка подденьте её вверх.
3. После щелчка аккуратно вытяните шлейф.

Now you can begin removing the motherboard. It is attached to 15 screws different sizes (see table below). Remember the location of each screw — during assembly it is easy to confuse them, which will lead to damage to the board!

Screw type	Quantity	Location	Features
PH00 (cross)	8 pcs.	Along the perimeter of the board	The longest ones - do not overtighten!
Y00 (five-beam)	2 pcs.	Under the SIM tray	Easy to lick off - use a swing screwdriver
Flat 1.5mm	5 pcs.	Around the camera and speaker	Short ones - don't lose them!

After unscrewing all the screws, the board must be carefully lifted using a mediator, starting from the connector side USB-C. Be careful: attached to the board 3 loops:

1. Plume fingerprint scanner (fragile, breaks easily!).
2. Plume rear camera.
3. Plume display (the widest).

⚠️ Attention: If you parse Redmi Note 9 Pro (not the usual Note 9), then a different type of board mounting is used - with additional metal clamps. Don't confuse the models!

What to do if the screw is leaking?

If the screw head is licked, try:

1. Place a rubber gasket (for example, from a handle) on the screwdriver for better grip.

2. Use a screw extractor (sold in phone repair kits).

3. As a last resort, drill out the screw with a drill with a thin drill bit (0.8 mm), but this is risky for the board.

Replacing the battery: nuances and choice of spare parts

Battery Redmi Note 9 (model BM4A) has a capacity 5020 mAh and is attached with double-sided tape. To replace it you will need:

1. Peel off the old battery. Use isopropyl alcohol (90%+) and a plastic spatula. Apply rubbing alcohol to the edges of the battery to dissolve the adhesive.
2. Clear site from glue residues. Use a lint-free cloth and rubbing alcohol.
3. Install a new battery. Before gluing, check that the contacts are not dirty or bent.

When choosing a replacement, pay attention to:

• 🔋 Capacity: original - 5020 mAh, but some Chinese analogues have 4500–4800 mAh.
• 🔌 Fast charge compatible: Cheap batteries may not support 18W.
• 📏 Thickness: original - 3.85 mm. Thicker batteries will not fit into the case.

Recommended spare parts manufacturers:

• ZOP Power - high-quality analogues with a guarantee.
• Baseus — batteries with pre-applied glue.
• Original Xiaomi (article MBY0027CF) - the most reliable, but expensive.

Disassembling the screen and replacing the display

Screen Redmi Note 9 (model JDI NT36672A) glued to the frame using LOCA glue, so replacing it requires special care. If your glass is cracked, but the matrix is intact, you can limit yourself to replacement touchscreen (sensory layer). If the matrix is ​​damaged (artifacts, dead pixels), you will have to replace the entire display module.

To replace the screen you will need:

1. Heat the screen up to 70–80°C (use a hairdryer or hot plate).
2. Pry off the glass with a plastic pick, starting from the bottom edge (there are fewer loops there).
3. Disconnect the cables:
   • Plume display (wide, 30-pin).
   • Plume fingerprint scanner (thin, 8-pin).

Cost of spare parts for the screen:

Part type	Price (RUB)	Difficulty of replacement
Touchscreen (glass + sensor)	1 200–1 800	Medium (requires LOCA glue)
Full display module (OLED)	3 500–5 000	High (you need to resolder the cables)
Fingerprint scanner cable	300–500	Low (easy to replace)

⚠️ Attention: When replacing the screen with Redmi Note 9 there is often a problem with auto brightness. This is because the new display may have a different light sensor. Solved by flashing the calibration module via Fastboot.

Frequent breakdowns and their elimination

Redmi Note 9 has several typical “diseases” that can be eliminated on your own:

• 🔊 Speaker doesn't work:

  Most often the problem is oxidation of the contacts or damage to the cable. Check integrity metal mesh speaker (it may move away from the body). Solution: cleaning with alcohol or replacing the speaker (part number 1601-00008).

• 📸 The camera gives an error:

  Usually associated with contamination or damage to the loop. Try reconnecting it. If it doesn’t help, check the contacts on the board (there may be microcracks).

• 🔋 Rapid battery drain:

  Check current consumption in sleep mode (must be <50 mA). If it is higher, the software or a “broken” battery is to blame. Solution: replace the battery or reset to factory settings.

• 📶 Poor network signal:

  B Redmi Note 9 The antenna cable often comes off (a thin black wire near the SIM tray). Gently press it down or replace it.

If the phone does not turn on after disassembling, check:

1. Is it connected? battery (sometimes the cable is not fully inserted into the connector).
2. Integrity power buttons (its cable may come off if the cover is removed carelessly).
3. Availability short circuit on the board (checked with a multimeter in the "testing" mode).

Assembling the phone: procedure and testing

Assembly Redmi Note 9 should proceed in the reverse order, but taking into account several nuances:

1. Check all cables for the presence of contamination. Clean your contacts pencil eraser (it removes oxides).
2. Apply new glue to the battery. Use double-sided tape 3M 9448A or special glue Tesa 61395.
3. Install rubber pads in place. Without them, the phone will lose protection from dust.
4. Tighten the screws in the following order:
   1. The screws around the camera (the shortest ones).
   2. Screws around the perimeter of the board.
   3. Screws under the SIM tray (five-spoke).

After assembly, be sure to test:

• 📞 Calls and microphone (call another phone and check the sound).
• 📷 All cameras (main, wide-angle, front).
• 🔋 Charging (connect the charger and make sure there is current flowing).
• 👆 Fingerprint scanner And screen sensor.

⚠️ Attention: If your phone overheats after assembly, you most likely forgot to apply thermal paste per processor. B Redmi Note 9 it is located under the metal plate on the board - don't forget to return it!

FAQ: answers to frequently asked questions

❓ Is it possible to disassemble Redmi Note 9 without a hair dryer?

Theoretically, yes, but the risk of damaging latches or cables increases significantly. The glue under the cap is very strong, and without heating the pick will slip. If you don't have a hairdryer, use hot water (place the phone in a bag and put it in water for 2-3 minutes), but this is less reliable.

❓ How much does it cost to replace a battery at a service center?

Cost of battery replacement in official services Xiaomi — from 2,500 to 3,500 rubles (with work). In unofficial workshops the price is lower: 1,500–2,000 rubles. However, they often install non-original batteries that last less.

❓ How to check if the original battery is installed?

Original battery Redmi Note 9 has:

• Inscription Xiaomi BM4A on the label.
• QR code that can be scanned (leads to the Xiaomi website).
• Black shrink film with logo Mi.

Counterfeits are usually lighter in weight and have blurry lettering.

❓ What to do if the touchscreen does not work after disassembling?

The reasons may be as follows:

1. The touchscreen cable is not fully inserted into the connector on the board.
2. The cable is damaged (check for breaks).
3. The contacts on the screen itself have come off (you need to warm it up with a hairdryer and press it).

If all else fails, the display module needs to be replaced.

❓ Is it possible to replace only the back cover?

Yes, but this is one of the most difficult operations. A new cover costs 800–1,500 rubles, but to install it you need:

1. Transfer all rubber gaskets and buttons from the old cover.
2. Glue it with double-sided tape (original glue Xiaomi not sold separately).
3. Heat with a hairdryer for better adhesion.

Without experience, it is better to contact a workshop.