How to diagnose Samsung Galaxy A40 Charging Problems

Introducción

This guide will help you diagnose the Samsung Galaxy A70, Samsung Galaxy A50, and the Samsung Galaxy A20. This guide might also work for other Samsung models.

Resumen del Video

Paso 1 +5V line

How to diagnose Samsung Galaxy A40 Charging Problems, +5V line: paso 1, imagen 1 de 3

How to diagnose Samsung Galaxy A40 Charging Problems, +5V line: paso 1, imagen 2 de 3

How to diagnose Samsung Galaxy A40 Charging Problems, +5V line: paso 1, imagen 3 de 3

This is the +5V line from the Charging port to the Motherboard.

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Paso 2 Back cover removal.

How to diagnose Samsung Galaxy A40 Charging Problems, Back cover removal.: paso 2, imagen 1 de 3

How to diagnose Samsung Galaxy A40 Charging Problems, Back cover removal.: paso 2, imagen 2 de 3

How to diagnose Samsung Galaxy A40 Charging Problems, Back cover removal.: paso 2, imagen 3 de 3

Warm the device to soften the adhesive.
Use Sanction cup, Plastic tools and isopropyl alcohol.
Remove the silver Phillips screws from the device's frame.

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Paso 3 Fingerprint sensor

How to diagnose Samsung Galaxy A40 Charging Problems, Fingerprint sensor: paso 3, imagen 1 de 3

How to diagnose Samsung Galaxy A40 Charging Problems, Fingerprint sensor: paso 3, imagen 2 de 3

How to diagnose Samsung Galaxy A40 Charging Problems, Fingerprint sensor: paso 3, imagen 3 de 3

Remove the plastic cap from the Fingerprint flex cable connector and disconnect the cable.
Remove the SIM Tray.

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Paso 4 Middle frame removal

How to diagnose Samsung Galaxy A40 Charging Problems, Middle frame removal: paso 4, imagen 1 de 3

How to diagnose Samsung Galaxy A40 Charging Problems, Middle frame removal: paso 4, imagen 2 de 3

How to diagnose Samsung Galaxy A40 Charging Problems, Middle frame removal: paso 4, imagen 3 de 3

Use a plastic tool to separate the back cover from the frame. Start from the SIM tray hole.
Disconnect the battery.

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Paso 5 Measurement

How to diagnose Samsung Galaxy A40 Charging Problems, Measurement: paso 5, imagen 1 de 3

How to diagnose Samsung Galaxy A40 Charging Problems, Measurement: paso 5, imagen 2 de 3

How to diagnose Samsung Galaxy A40 Charging Problems, Measurement: paso 5, imagen 3 de 3

Disconnect the main flex cable and connect the charger.
Use a multimeter to measure the voltages at the large end pins of the FPC connector of the charging board. (See the second image)
If the reading is okay (~5V) continue with the next step, if not - change the Charging board.
Attach the main flex cable and measure the large end pins of the Main flex FPC connector - pic.3.
If the reading is okay, continue with the next step, if not - change the Main flex cable.

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Paso 6

How to diagnose Samsung Galaxy A40 Charging Problems: paso 6, imagen 3 de 3

Remove the adhesive rubber around the main flex connector on the logic board.
Use some flux and a soldering iron to re-solder the first pin of the motherboard FPC.

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