How to Fix a Samsung Galaxy S10 Plus That Does Not Turn On/Power On

A current leakage of 52 mA on the motherboard indicates a possible issue with the main power supply line.

• Install the motherboard and connect the display and power cable for testing.
• Press the power button to see if there's any change in the reading, but it remains the same.
• Use a multimeter's diode mode to measure several power supply lines on the motherboard.

The inductor L5039 is shorted to ground, indicating a faulty component.

Open the schematic.

• Observe that L5039 connects directly to VBAT and U8031.

Verify the power IC U8031 for any signs of damage or burnout.

• Attach the motherboard to the holder, applying paste flux to the power IC U8031.
• Heat with a hot air gun set at 340°C and airflow 3 to remove the IC.

Fault diagnosis: Diode mode measurement confirms a short circuit on the main power supply line.

• Clean the bonding pad with solder wick.
• Measure the inductor L5039 using the multimeter's diode mode. Expected value: 289 (normal).
• Clean the bonding pad with PCB cleaner, then apply paste flux.

Set a hot air gun to 340°C and 2 airflow units.

• Solder the new IC using the hot air gun.

Allow the motherboard to cool completely before proceeding.

• Connect the power cable to the motherboard.
• Use tweezers to trigger a boot-up cycle.

• Once complete, install the motherboard into the phone.
• The phone should turn on normally and indicate that the fault has been cleared.