Disassembly/Repair of the mobile device Xiaomi Redmi 9 (Xiaomi Redmi 9 M2004J9AG) with each step description and the required set of tools.

⚠️ Before disassembling, do not forget to turn your phone off.

Use the Key tool (aka Needle) or Paperclip. Push the tip all the way into the hole until the tray ejects, and then pull the tray of SIM and Memory card (Micro SD) out.

⚠️ Pay attention! The tool must be inserted into a hole on the edge of the phone's housing. Do not press too hard. It may break the tray eject mechanism.

Using a spudger or a plastic pick, carefully, around the edge, detach the back cover clips, and remove it.

Do not insert the tool deeply or bend it. Otherwise, the housing may be tampered with or damaged.

⚠️ Be careful when opening the cover from the volume and power buttons side. Thin cable and fragile buttons are straightforward to damage.

Using a screwdriver (Phillips 1.5 mm PH000), unscrew the 10 screws.

Remove the bracket holding the connectors.

Pry up the fingerprint sensor connector and remove the cover with antennas that protect the printed circuit board (PCB).

Try to lift the covers by the edges and not push anything between them to not accidentally touch or short-circuit anything on the PCB.

Disconnect the battery connector as soon as possible.

ℹ️️ The Xiaomi Redmi 9 M2004J9AG model has a battery BN54 with 5020 mAh capacity (aka rechargeable battery).

⚠️ It is highly recommended to disconnect the connector to avoid possible short circuits during disassembly.

Also, try not to use a metal tool to disconnect the rechargeable battery connector or do it carefully.

Using a screwdriver (Phillips 1.5 mm PH000), unscrew 7 screws.

Remove the loudspeaker assembly with antennas.

Using a screwdriver (Phillips 1.5 mm PH000), unscrew one screw securing sub-board.

Carefully, preferably from the edge, disconnect the connectors and remove the inter-board cable connecting the mainboard to the daughterboard (also known as the sub-board).

⚠️ Be careful when removing the cables from the connectors, the cables are pretty thin, and it is easy enough to break them or damage the contact tracks inside.

ℹ️️ An arrow on the FFC cable (flexible flat cable) indicates its correct position.

Pry up the coaxial cable connector.

Remove the sub-board. It is glued to the frame with metalized tape, so to facilitate the process, the board can be heated a bit.

ℹ️️ The board contains a charging port (Micro USB), microphone, headphone jack socket, spring contacts for the speaker, and an antenna unit.

⚠️ It is not necessary to insert the tool under the board when removing the sub-board. Internal components could be damaged.

Open the cover securing the cameras.

Pry up the connectors and remove three rear cameras and one front (selfie) camera.

Pry up the connectors of the display module cable, coaxial cable.

⚠️ Be careful when removing the cables from the connectors, the cables are pretty thin, and it is easy enough to break them or damage the contact tracks inside.

Carefully remove the printed circuit board. There is no need to use a lever or try to reach the board by force. Make sure that nothing is getting in the way or holding the board.

⚠️ Do not bend the circuit board when removing it or push tools under it. Unbeknownst to yourself, you can damage components or cables from the inside.

Pry up the connector and remove the rear camera.