How to disassemble Xiaomi Redmi 4 Pro: a complete guide with nuances

Xiaomi Redmi 4 Pro (codenamed markw) remains popular with users even years after its release, and its reliability and maintainability make it an excellent candidate for self-service — whether it’s replacing a charging connector, battery or display module. However, disassembling this device has a number of features that are important to consider so as not to damage fragile plumes or lose small parts.

Many owners face the challenge of disassembling the Redmi 4 Pro after a fall when the touchscreen stops working, or when the battery swells with time. Unlike Xiaomi's flagship models, which often use adhesive foundations and complex latches, the design here is more beginner friendly. But that doesn't mean that the process can be done on the knee - without the right tools and sequence of actions, the risk of damaging the board or plumes remains high.

In this article, we will go into detail about the entire process, from the preparation of the workplace to the reverse assembly, focusing on the typical errors that lead to a broken display or a lack of network after dismantling. And if you have never held a screwdriver for your phone before, don't worry: our guide is designed for users with zero experience.

Preparation for disassembly: tools and security measures

Before you start, make sure you have everything you need. The Redmi 4 Pro doesn't require professional equipment, but you can't do with a single screwdriver. Here's the minimum set:

• 🔧 Plastic blades (2-3 (a) - for separation of the body without scratches.
• 🔩 Cross screwdriver PH00 — All the screws in the phone are exactly this size.
• 🧲 Magnetic mat or container - so as not to lose the screws (there are 12 pieces!).
• 🔥 Hair dryer or thermo-air station – if you plan to take off the screen (the glue softens at 60-80)°C).
• 📱 Suction cups (2 pcs) - will help to smack the front panel after heating.
• 🔍 Lupe or magnifying glass - to inspect small details on the board.

If you're disassembling your phone because of a bloated battery, don't use metal tools to extract it, which can short circuit and ignite, so you better prepare insulated tweezers and gloves in advance, and make sure the room is well ventilated, and when lithium-ion batteries puncture, toxic gases are released.

⚠️ Warning: If the phone has been in water or humid environment, dry it for at least 48 hours in rice or silica gel before disassembling.

It will be useful to take a photo of the original assembly before the start of work - this will help to correctly arrange the plumes and screws during the reverse assembly. And if you have never held a soldering iron in your hands, it is better to entrust the replacement of chips (for example, for example, the replacement of chips, UFS-chip PMIC) Professionals – here you need experience and special equipment.

Step 1: Remove the back cover and remove the battery

Start by turning off your phone and retrieving it. SIM-The back cover of the Redmi 4 Pro is mounted on latches and double-sided tape, so it can be removed without heating:

1. Insert a plastic blade into the gap between the lid and the body at the headphone jack.
2. Smoothly drive the blade along the perimeter, alternately snapping clips. Do not force - if the lid does not respond, check if all latches are released.
3. When you take the lid off, you'll see the battery covered with a black film, and underneath it, there's a power connector, and you have to disconnect it first to avoid short circuits.

The battery is glued to the body, but the glue is not as aggressive as the new models.

• 🔋 Tap the battery with a plastic blade on the side (not from the end!).
• 🧹 If the glue is too sticky, heat the body with a hair dryer (not higher than 60).°C!) for 1-2 minutes.
• ⚠️ Don’t pull the battery plume – it easily breaks off from the board!

⚠️ Attention: If the battery is swelling, don't try to pin it down or puncture it. Lithium-ion cells can ignite if damaged, in which case it's better to dispose of the battery immediately at a special reception point.

After the battery is removed, check it for damage. The normal capacity for the Redmi 4 Pro after 2-3 years of operation is about 3000-3500 mAh (originally 4100 mAh). If the battery lasts less than an hour and a half, it is definitely time to replace it. MDY11 or DM-09.

Step 2: Unconnecting the plumes and removing the motherboard

Now that the battery is off, you can start dismantling the board, and at this point, the key is not to confuse the way the plumes are disconnected. Redmi 4 Pro has three.

Procedure:

1. Unscrew 12 screws that fix the board (they are of different lengths - remember the location!).
2. Remove the metal screen from the board (it is attached to the clips).
3. Disconnect all the plumes, starting with the display. Use plastic tweezers or a spatula to gently lift the latches of the connectors.
4. Remove the board by holding it around the edges. Don't touch the chips with your fingers, because static electricity can damage them.

If you disassemble your phone due to network problems (e.g., not catching) 4G), pay attention RF-The path is a metallized track near the antenna connector, and often oxidation or a break here causes a loss of signal.

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If the screws don't unscrew, don't force -- probably the screwdriver is the wrong size. In the Redmi 4 Pro, all the screws are screws. PH00, But sometimes they come across damaged slats, and then you can use a drop of superglue on the screwdriver, and you can let it freeze a little bit and you can gently unscrew it.

Step 3: Disassemble the display module (if required)

Replacing the screen is one of the most difficult things to do in the Redmi 4 Pro, because it's glued to the frame, and you can't do without heating.

• 🔥 Hair dryer with temperature adjustment (optimally 70-80)°C).
• 🧴 Isopropyl alcohol (90%+) — glue-residue.
• 📏 Plastic mediators (0.2–0.3 mm) – so as not to damage the plumes.

Step-by-step:

1. Warm up the screen evenly around the perimeter for 3-5 minutes. Do not hold the hair dryer in one place - this can melt plastic parts.
2. Stick the suction cups to the bottom of the screen (where the Home button is located) and pull up. If the screen doesn't lend itself, warm up for another 1-2 minutes.
3. Put the mediator in the gap and carefully lead along the edge, separating the glue. Be careful in the area of the plume of the touch screen - it is located on the left!
4. After removing the screen, clean the frame of the glue residue with alcohol. The new screen is glued to a two-way tape (for example, 3M 9448A).

If you only change the glass, not the entire display module, you will need to split. OCA-To do this, use a special Wire Cut and heat up to 100.°C. However, without experience, it is better to order a new module in the assembly - separation often ends in damage to the matrix.

Step 4: Replace the speaker, microphone or camera

These components are the easiest to change, because they don't require disassembly of the display module.

🔊 Dynamician

It's located at the bottom of the phone under a metal grille to replace it.

1. Unscrew 2 screws, attaching the speaker to the body.
2. Disconnect the plume from the board (it is short, so don't pull the wires!).
3. Remove the speaker and install a new one. The original one has a marking. DSN-AL1006.

🎤 Microphone

The Redmi 4 Pro has two microphones: the main one (near the charging connector) and the noise suppressor (upper, near the camera).

• The main microphone is glued to the board - carefully tuck it with a spatula.
• Noise-canceling microphone is attached to the body on a two-way tape.
• Before installing a new one, check the contacts on the board for oxidation (clean with alcohol if necessary).

📷 Camera.

The camera module is mounted on 2 screws and connected to the board with a flexible plume.

⚠️ Warning: Don't touch the lens of the new camera with your bare hands - fat marks will worsen the quality of the photo.

If the camera is replaced with an error 0xA00F4244 (Unknown error, check for it:

• The density of the plume to the connector.
• Integrity of contacts on the board (sometimes they peel off when overheated).
• Matching the camera model (original — OV13853 primary and GC2355 frontal).

Step 5: Diagnostics and repairs of the board (for experienced)

If the phone doesn't turn on, charge or overheat, the problem can be in the board. Redmi 4 Pro most often fails:

• 🔋 Power chain (microchip) PMIC — MT6351).
• 📡 Communication module (RF-transceiver chip — MT6169).
• 💾 Memory (eMMC chip — H9TP32A4GDMCPR).

For diagnosis, you will need:

• 🔬 Loupa or microscope (magnification) ×10–×20).
• 📊 Multimeter in vertebral mode or DC-measurement.
• 🔥 Soldering station with a temperature of 300-350°C (to replace chips).

Example of diagnostics of lack of charging:

1. Check the tension on the contacts USB-sleeves (should be) 5V when connected to the zoo).
2. Call the circuit from connector to chip. PMIC (pin VCC_MAIN and GND).
3. If there is a voltage, but the phone does not respond, the problem is PMIC or firmware.

⚠️ Attention: Replacement BGA-A chip (like a Snapdragon 625) is almost impossible to use without professional equipment at home. Even if you find a donor board, you need an infrared heater and experience with soldering. BGA-ball-ball.

If the board has visible damage (blackened tracks, bloated capacitors), it is better to order a new one on AliExpress (article: Redmi 4 Pro Motherboard markw). ₽, new - 8000-12,000 ₽.

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Before you buy the board, check its compatibility! In Redmi 4 Pro, there are 2 revisions of the boards: markw (global version) and prada (Chinese version).

Step 6: Build your phone and check its health

Reverse assembly is as important as disassembly. Here are the key points:

1. Make sure all the plumes are connected to the end – they must click in the connectors.
2. Write the screws in the same order that you twisted them, screws of different lengths, if you mix them up, you can damage the board.
3. Before installing the battery, check that there is no oxidation on its contacts (clean with a stripe if necessary).
4. Press the back cover evenly, starting from the top, so that all latches fall into place.

After assembly, turn on the phone and check:

• 📶 Network operation (call, check mobile Internet).
• 🔋 Charging (plug the ROM and make sure the current is going on).
• 🎵 Sound in speaker and microphone (record voice message).
• 📷 Camera (take photos on both cameras).
• 👆 Touchscreen (swipe your finger across the screen).

If something doesn't work, don't panic. Go back to the appropriate section and check:

• Connect plumes (especially if the screen or camera is not working).
• Integrity of antenna contacts (if no network is available)
• Battery polarity (if the phone is not turned on)

If the phone overheats or discharges quickly after assembly, the most likely problem is:

• Incorrectly installed battery (check contacts).
• Damaged plume touchscreen (can cause increased power consumption).
• Short circuit on the board (multimeter diagnostics are needed).

Common Mistakes and How to Avoid Them

Even experienced craftsmen sometimes make mistakes when disassembling the Redmi 4 Pro.

Another common problem is loss. IMEI And this happens when you disconnect the battery when you turn on the phone or damage it. NVRAM-The memory section. IMEI You can use Engineer Mode (type #36446337##) but you need a backup file or knowledge of the original numbers.

If the phone does not turn on after assembly, but reacts to charging (the indicator burns), try:

1. Connect to a PC and check if it is defined as Qualcomm HS-USB QDLoader 9008 (means emergency charge).
2. Swipe through the Mi Flash Tool (download the markw firmware on xiaomifirmwareupdater.com).
3. If the firmware doesn't help - the problem is in the hardware (check out) PMIC feed-chain).

FAQ: Frequent questions about Redmi disassembly 4 Pro