OPPO A35 can’t be recharged after water is injected.

OPPO A35 can’t be recharged after water is injected.

Observing the motherboard after disassembling, the corrosion is not serious. When the battery is not installed, plug in the charger for the mobile phone, and measure that the positive voltage of the battery is only 1V, which is obviously low. After replacing the charging IC, the charging current returns to normal.

Machine model: OPPO A35

Fault phenomenon: the customer described that the mobile phone could not be charged after it was filled with water. When the charger was plugged in, the mobile phone had a charging sign, but the charging current was very small.

OPPO A35 can’t be charged with electricity after entering water. Maintenance Figure 1

OPPO A35 can’t be charged with electricity after entering water. Maintenance Figure 2

Fault analysis: the combination of the water inlet machine and the failure to charge electricity is either the chip has a problem or the path is corroded.

Maintenance process:

Observing the motherboard after disassembling, the corrosion is not serious. When the battery is not installed, plug in the charger for the mobile phone, and measure that the positive voltage of the battery is only 1V, which is obviously low. After replacing the charging IC, the charging current returns to normal.

OPPO A35 can’t be charged with electricity after entering water. Maintenance Figure 3

However, after charging for a few seconds, the mobile phone suddenly prompts “abnormal charging”.

OPPO A35 can’t be charged with electricity after entering water. Maintenance Figure 4

This kind of problem is mostly caused by the fault of battery positive detection signal line. Open Xinzhizhao software, and check the point bitmap to know that the positive electrode of the battery is connected to the main power supply through a resistor.

OPPO A35 can’t be charged with electricity after entering water. Maintenance Figure 5

The negative electrode of the battery is also connected to the main power supply, which shows that the positive and negative electrodes of this type of battery have detection channels.

The resistance on the line of the battery positive electrode is transparent sealant, which can be waterproof.

The main power supply is without sealant, and no obvious corrosion trace is found after observation, so a small amount of rosin is added to the main power supply, and the main power supply chip is soldered with a direct wind gun.

After the main power supply is soldered, the motherboard is put back into the mobile phone to start the test. The mobile phone can be charged normally and the fault is perfectly repaired.