Disassembly/Repair of the mobile device Nokia 3.1 Plus TA-1104 with each step description and the required set of tools.

Use the ejection tool (aka Needle) or Paperclip. Push the tip all the way into the hole until the tray ejects, and then pull the tray out. Should do it for each of the SIM and Memory card (Micro SD) trays.

⚠️️ 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 screwdriver (Star Shape 0.8mm Pentalobe), unscrew the two screws at the end of the phone.

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.

⚠️️ Pay attention to the fingerprint sensor cable located on the inside. It is better to unstick the fingerprint sensor body from the back cover at this point.

Before, we have one screw under the fingerprint sensor body, so if the fingerprint sensor is glued to the bracket, we have to unstick it first.

Using a screwdriver (Phillips 1.5 mm PH000), unscrew the three screws and remove the brackets holding the connectors.

Disconnect the battery connector as soon as possible. It is better to use a non-metal or plastic tool to avoid any damage.

ℹ️️ The Nokia 3.1 Plus TA-1104 model has a battery HE363 with 3500 mAh capacity (aka rechargeable battery).

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

Pry up the connector and remove the fingerprint sensor.

Unstick the cover hiding the screw. After, using a screwdriver (Phillips 1.5 mm PH000), unscrew the seven screws.

Pry over the edge and remove the loudspeaker assembly.

Disconnect the coaxial cable connector, inter-board cable connector.

⚠️️ Do not pull on the cable or pry it with a sharp tool, the connectors are pretty weak and break easily, or the cable falls out of the end (lug).

Remove the sub-board. It may be glued to the frame or attached with attachments like latches or hooks, so be careful.

ℹ️️ The sub-board contains a charging port (Micro USB), microphone, spring contacts for the speaker, vibration motor, and an antenna unit.

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

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

Carefully remove the bracket holding the headphone jack socket.

Disconnect the connector on the motherboard, and remove the front (selfie) camera.

Pry up the connector of the display module cable, inter-board cable, and 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 circuit board by force. Make sure that nothing is getting in the way or holding the circuit board.

The motherboard, also, may be attached with attachments like latches or hooks, be careful.

⚠️️ 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.

Disconnect connectors on the motherboard, and remove the assembly of the two rear cameras.