The iPhone 6 Plus had fallen into water, causing the front camera, receiver, and proximity sensor to stop working. The technicians repaired the device by replacing damaged components like the front camera socket and audio chip. They also found that the touch control chip U2403 was causing a low voltage issue for the proximity sensor. Removing this chip restored normal voltages and functionality.

1. How to fix iPhone 6 Plus camera and receiver not
working
Last week, my friends iPhone has dropped into water,
then the camera is unworkable and receiver has no
sound as well as the screen does not turn black during
calls (cannot sense distance).It really make him
depressed. We sent the motherboard to vipprog, let's
see how the technicians fixed it.
ISSUE:
Customer sent an iPhone 6 Plus motherboard. He said
his iPhone has dropped into water, so the front camera
is unworkable and receiver has no sound as well as the
screen does not turn black during calls (cannot sense
distance)
SOLUTION:
1. Assemble the board to tester assembly and test,
finding the front and rear cameras are unworkable,
receiver has no sound, the screen does not turn black
during calls and sound cannot be recorded.
2. Observing motherboard, we find that the touch

2. assembly is fixed and there are jump wires. We doubt
that the high temperature may cause the above
problems. Starting from front camera socket J1111, we
can see that the socket is split and the light‐sense
control tube Q1101 has been torn down. Replace the
front camera socket and solder light‐sense control tube
Q1101. The material object of light‐sense control tube
Q1101 is shown in picture 1‐1.
3. Measure the diode data to ground of pin 1, 2 of front
camera socket J1111 (picture 1‐2) and the data is infinite.
The two pins are receiver signal. Replace the audio chip.
The material object of audio chip is shown in picture 1‐3.

3.
4. After replacing the audio chip, measure the diode
data again and data now is normal. We continue to
measure the diode data to ground of front camera
socket J1111, finding that pin 7 camera 2.85V’s data is
higher than normal one. It maybe caused by empty
solder of the 2.85V transmission tube. Then we remount
the U2301 chip, and measure the diode data to ground
of J1111 pin 7. Now the data is normal. The material
object of U2301 is shown in picture 1‐4.

4.
5. Assemble the board and test the front camera and
receiver, which are normal now. There leaves an
unsettled problem‐the screen does not turn black during
calls. Measure the diode data to ground of J1111, which
is normal. Measure the power supply of J1111’s pin 23
proximity sensor which is 3.3V and it is normal. Measure
the power supply of open signal circuit of J1111’s pin 25
proximity sensor, which is 1.8V and it is lower that
normal one. Check the bitmap and find that the opening
signal is connected to pin C2 of main touch screen chip
U2401, as shown in picture 1‐5.

5.
6. Check the circuit diagram(picture 1‐6) and we know
that the resistor R2405 pull up opening signal of
proximity sensor to PP1V8_GRAPE from which the
opening signal get power. Measure the voltage of
resistor R2405 pin 1, which is lower that normal one.
Then measure the diode data to ground and data is
about 30. The material object of R2405 is shown in
picture 1‐7.

6.
7. Checking the PCB bitmap, we know that
PP1V8_GRAPE connects main touch screen chip U2401,
main power supply U1202, touch control tube U2403
and part of resistors and capacitors, as shown in picture
1‐8.

7.
8. Many components are connected with PP1V8_GRAPE
and it is not completely short circuit to ground. We
cannot use the burn‐in method either, so remove the
relevant components one by one. The diode data does
not change after removing the main touch screen chip
U2401. Then remove the connected filtering capacitor
and the data remains the same. Observing under
microscope, we find that U2403 has been replaced by
the last repairman. Use air hot gun to tear down U2403.
Now measure the diode data to ground and it is normal.
Tear down a touch control tube U2403 from a circuit
board to assemble it and turn on iPhone to test. Trouble
is removed.