Diagnose A Samsung Galaxy A40 Charging Problem

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

Worm the device to soften the adhesive.

Use Sanction cup, Plastic tools and isopropyl alcohol.

Remove the silver Phillips screws from the middle frame.

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

Remove the SIM Tray.

''Use plastic tool to separate the middle frame. Start from the SIM Tray hole.'

First of all disconnect the battery.

Disconnect the Main flex cable and connect the charger.

Use a multimeter to measure the voltages at the 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.

Remove the adhesive rubber.

Use some flux and soldering iron to re-solder the first pin of the Mother board FPC.