Share Water Damaged iphone 6s Current Jumps Trouble

1. Water Damaged iPhone 6S Current Jumps Trouble
When your iphone 6S dropped into sea. It sounds a bit
implausible, but it can be existent. If it happens, you
should do these. First of all, don't panic, iPhones actually
are billed as waterproof, so you might be in no trouble at
all. Either way, the first step is to turn off your handset
then dry it off with a clean cloth or towel first to assess
the damage. Pop out your SIM card too, just to minimize
the risk of it getting affected. You can must trust it will
be well and vipprog can help you.
Issue:
IPhone 6s has been dropped into sea and it turn off
current jumps at 0mA and 120mA repeatedly.
Solution:
1. Connect the adjustable DC power supply to check
current and it shows electricity leakage is 60mA and
120mA if press the power button. Then it drops back to
0mA and repeats the jump process.
2. Remove CPU and the shield cover on baseband,
finding four eroded places. They are backlight power
supply chip U4020, display power supply chip U4000,
charging management chip U2300 and small audio chip

2. U3700. As for the water-damaged iPhones, we first take
photos for the watered places and then clean the
motherboard. That will be beneficial, because if we find
some problems during the repair process, we can refer to
those photos to exclude badly eroded components.
3. After cleaning, we energize the motherboard and find
that the electricity leakage current turns less, only about
20mA. After turning on, the current jumps from 70mA to
0mA repeatedly.
4. Measure the power supply voltage of CPU U0600,
finding no abnormality. Measure the voltage of I2C bus,
finding that the signal I2C0_AP_SCL only has 1.1V. The
I2C0 bus in circuit diagram is shown in picture 1-1. The
I2C0 bus in bitmap is shown in picture 1-2. The material
object of I2C0 bus is shown in picture 1-3.

3. 5. Deenergize motherboard and measure the diode data
of I2C bus. There are 404 and 430 which is normal.
Viewing the eroded components photos, we feel that the
display power supply is damaged, because the backlight
chip is painted with glue, which is not easy to be
damaged. Remove the display chip U4000.
6. After removing the display chip U4000, energize it,
but the current is still the same. While I2C0 bus voltage

4. turns normal. This problem may be caused by power
supply chip U2000 and backlight chip U4020.
7. That the backlight chip U4020 causes the turn on
failure is related to two groups of signal. One is I2C0 bus,
the other is backlight brightness adjustment
signal?backlight chip DWI bus which runs to power
supply and CPU. The DWI bus interface in schematic
diagram is shown in picture 1-4.
8. The backlight chip DWI bus has SDI and SCK two
signals. By measuring the diode data to ground, we can
know whether backlight chip U4020 is workable or not.
SCK can be measured at the resistor R4020 in picture 1-5
and SDI can be measured at the test point PP1002 in
picture 1-6.

5. 9. Measuring the diode data to ground of R4020, we find
that it is short circuit. Remove the backlight chip U4020
and energize motherboard to turn it on. The current
jumps to 1A. After assembling backlight chip U4020 and
display chip U4000, the white Apple logo appears and
iPhone gets into IOS normally.
10. When dealing with the problems about the turn on
failure after being watered, we can ignore the removed

6. chips if they do not effect the turn on process. If the
current jumps normally, we reassemble them.