How to disassemble Xiaomi Redmi Note 9 Pro: detailed instructions with photos and tips

The Xiaomi Redmi Note 9 Pro may need to be disassembled to replace the battery, repair the screen, clean up dust or diagnose internal components. Although the model was released in 2020, its design remains relevant for many users - especially given the prevalence of the device and typical problems (for example, battery bloating after 2-3 years of operation). In this article, you will find a step-by-step instruction taking into account the features of this model, including the nuances of attaching the rear cover, the location of the plumes and potential "pipes".

It’s important to understand that the Redmi Note 9 Pro (codenamed joyeuse) has a non-removable battery and adhesive back panel, which makes it difficult to disassemble compared to models with removable covers (for example, the Redmi 4X). If you have never disassembled smartphones before, we recommend that you first familiarize yourself with the list of tools and safety rules. Errors at the opening stage of the case can lead to damage to the display plume or to the antenna contacts – and this is already expensive repair.

Before you start, answer two questions:

1. Do you have spare parts (such as a new battery or screen) if the disassembly involves a replacement?
2. Are you ready for the fact that after opening the case, the tightness of IP53 (splash protection) will be violated?

If the answers are yes, let’s start!

What tools will be needed to disassemble

To properly disassemble the Xiaomi Redmi Note 9 Pro, you need a specialized set of tools, and using improvised tools (knives, screwdrivers of the wrong size) can damage plastic latches or scratch the body.

• 🔧 Plastic blades (suction cups) - for separation of the back cover (minimum 2 pieces, thickness 0.2-0.4 mm).
• 🔨 The screwdriver. PH00 — for shell screws (normal) PH0 If you don't, you'll tear the slats!).
• 🔥 Dryer or thermo-air station - for softening the glue (temperature 60-80)°C).
• 🧲 Magnetic mat or organizer - so as not to lose screws (there are more than 15 pieces!).
• 📏 Plastic tweezers – to disconnect plumes (metal can damage contacts).
• 🔋 Isopropyl alcohol (90%+) — glue-cleaner.

If you are planning to replace the battery, prepare:

• 🔄 New battery (original — MBJ4058152, capacity of 5020 mAh).
• 🧴 Double-sided tape or glue B7000 — fixing.

Attention! Do not use metal blades to separate the lid - they conduct current and can close contacts on the board. Also avoid overheating the body with a hairdryer: if the temperature exceeds 90°C. There is a risk of damage OLED-Matrixes (in Redmi Note 9 Pro used) AMOLED-Samsung display).

Preparing the phone for disassembly

Before opening the case, you need to properly prepare the device, and neglecting these steps can lead to data loss or short circuit.

Turn off the phone (press Power + Volume up for 10 seconds)

Extract. SIM-microSD card and memory card

Discharge the battery to 20-30% (to avoid fire if damaged)

Remove the cover and protective film (if any)

Take a picture of the location of the screws before unscrewing-->

Pay special attention to the battery. The Redmi Note 9 Pro uses a lithium polymer battery, which can ignite if mechanically damaged (such as a blade puncture) and if you notice bloating, do not try to disassemble the phone without first cooling the battery (put the device in the freezer for 15-20 minutes, pre-wrapped in plastic).

We also recommend:

• 📱 Make a backup of data through Settings → System system → Backup.
• 🔌 Turn off fast charging (if the phone was on charge before disassembly, wait 30 minutes).
• 🧹 Clean the workplace of dust and metal objects.

💡

If the phone is not turning on and not responding to charging, don't rush to disassemble it. Try "resuscitation" first: plug it into the charger for 20-30 minutes, then press Power + Volume down for 15 seconds. In 30% of cases, this helps "wake up" the device.

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

The most important step is to detach the back cover, and in the Redmi Note 9 Pro, it's glued around the perimeter and it's also latched, and if you don't do it carefully, you can damage:

• 📶 Antenna contacts (located on the sides of the body).
• 🔊 Dynamic (glued to the lid at the bottom).
• 📷 Camera plume (passes near the top latch).

Follow this algorithm:

1. Heat the body with a hair dryer around the perimeter (keep it 5-7 cm away so you don't overheat). Start at the bottom of the body, where the USB-C connector is located.
2. Insert a plastic blade into the gap between the lid and the case (it is better to start at the corner next to the Volume up button).
3. Carefully drive the blade along the body, separating the latches. If the lid does not respond, warm up this area again.
4. Lift the lid 1-2mm and hold it with a second spatula or a suction cup. Don't pull too hard, there may be glued areas inside!

Common mistakes at this stage:

Disconnecting the battery and removing the motherboard

When you remove the back cover, you'll see a battery that's black-filmed and a motherboard with multiple plumes, and the first thing you need to do is turn off the battery to avoid short circuits in further manipulation.

Algorithm of action:

1. Find the battery connector (located at the bottom of the board, next to the USB-C port) and it's covered with a black plastic lock.
2. Carefully tuck the lock with a plastic spatula and disconnect the plume (pull the plastic part, not the wires!).
3. Wait 1-2 minutes - this will discharge the residual capacitors on the board.

Now we can start to extract the motherboard.

1. Unscrew all the screws (there are 12-14 pieces, different lengths - remember the location!) In the Redmi Note 9 Pro, the Y00 and PH00 screws are used.
2. Disconnect the plumes in that order: 📞 Display plume (top of board, under metal screen). 📷 Main camera plume (top left corner). 🔊 Dynamic plume (bottom part, next to the charging connector).

Carefully tuck the board with a plastic spatula and raise it at an angle of 30-45 °. Don't pull vertically - you can tear the antenna contacts!

💡

Never touch a board with your bare hands for metal elements (radiator, contacts). Static electricity can damage chips. Use an antistatic bracelet or at least touch an earthed object before work.

Attention! In the Redmi Note 9 Pro, the fingerprint scanner plume is very fragile and is under the board. If you're not planning to replace it, try not to touch this area. If the plume breaks, the scanner will stop working, and it will cost 30-50% of the cost of the phone to replace it.

Replacement of the battery: nuances and tips

If the purpose of disassembly is to replace the battery, then after turning off the old battery, you need to carefully remove it. In the Redmi Note 9 Pro, the battery is glued to the body with double-sided tape, which eventually turns into a thick mass.

• 🔥 Battery damage (fire risk!).
• 🧨 Thermosensor break (the phone will not charge).
• 🔧 Deformation of the body (if pulled too hard).

The right course of action:

1. Put the battery on the side with a plastic blade (where there are no plumes).
2. Drain isopropyl alcohol under the battery to dissolve the glue.
3. Carefully drive the blade under the battery, separating it from the body. If the resistance is too strong, add alcohol and wait 1-2 minutes.
4. After extraction, clean the body of glue residues with a napkin soaked in alcohol.

When installing a new battery:

• 🔋 Use only the original battery (article) MBJ4058152) or a certified equivalent (e.g. from ZMI).
• 🧴 Apply a thin layer of glue B7000 on the case before installation (do not overdo it - the surplus can get on the board!).
• 🔌 Connect the battery plume last after connecting all other components.

1. Correct connection of the battery plume (it should click when fixing).

2. no damage on the board (blackened or bloated capacitors).

3. Charger - try another (preferably original, with Quick Charge 4 support)+).-->

Build the phone: reverse order and check

The Xiaomi Redmi Note 9 Pro should be assembled in reverse order, but taking into account several critical points:

1. Connect the plumes last, starting with the display and ending with the battery.
2. Screw the screws cross-curl to avoid skewing the board.
3. Stick the back cover to a double-sided tape (for example, 3M 9448A), after cleaning the surface with alcohol.

After assembly, be sure to check:

• 📱 Turning on the phone (if not responding - check the power plume).
• 🔋 Charging (the battery icon should appear).
• 📶 Network and Wi-Fi (if there is no signal, check the antenna contacts).
• 📷 Cameras and fingerprint scanner (if not working, reconnect the plumes).

Attention! If the phone overheats or discharges quickly after assembly, you probably forgot to plug in the battery's thermosensor (a thin white wire that goes from battery to board), in which case you'll have to disassemble the device again.

Frequent Mistakes and How to Avoid Them

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

If you have a problem that is not in the table, try:

• 🔍 Check the error logs through Settings → The phone. → Version. MIUI (press 5 times on "Core").
• 📱 Reset to factory settings (if the phone turns on but is unstable).
• 🛠 Contact the service center (if the board or display is damaged).

FAQ: Answers to Frequent Questions