Share iphone 6s is unrespomsive when press the volume button

1. iPhone 6S is unresponsive when press the volume
button
If the volume button on your iPhone 6s suddenly
unresponsive or stops working, there could be a major
hardware problem or just a small software issue. Read
this steps could help you figure out which you’re dealing
with. Some tool of this article you can find in
vipprogrammer.com.
Trouble Phenomenon:
The volume button is not workable and has not been
recovered.
Repair Process:
1. After checking circuit diagram, we find that volume
button interface J4701 has three signal circuits, namely,
volume up, volume down and mute switch. The circuit
diagram of J4701 socket is shown in picture1-1.
2. Measure the voltage of pin 2,4 and 9 of J4791. The

2. voltage of volume up signal pin 4
BUTTON_VOL_UP_CONN_L is 0.6V while the voltage
of volume down signal pin 4
BUTTON_VOL_DOWN_CONN_L and voltage of mute
signal pin 9 BUTTON_RINGER_A_CONN are 1.8V.
After checking circuit diagram, we find that the three
signals do not have pull-up resistors, which suggests that
CPU offer the pull-up voltage. Deenergize volume button
interface J4701 and measure the diode data of the four
pins of J4701. The data is normal. The low voltage of
volume up signal BUTTON_VOL_UP_CONN_L could
be caused by electric leakage from some components on
this signal circuit. Capacitor C4713, voltage-regulator
diode DZ4713 and CPU U0201 are connected with this
signal, as shown in picture1-2. The material object is
shown in picture1-3.

3. 3. The showing data indicate that CPU is not pseudo
soldering. Remove the capacitor C4713,
voltage-regulator diode DZ4713 and measure the voltage
of volume up signal BUTTON_VOL_UP_CONN_L.
The voltage remains the same. The diode data is normal.
The voltage is abnormal even after some parts are torn,
which is obviously caused by a damaged CPU. We
cannot replace the CPU, but we can add a pull-up voltage
at the outside of CPU. After checking circuit diagram, it
is the most convenient to gain voltage from compass.
Connect a 1kΩresistor at the 1.8V end of capacitor
C3000. Jump a wire from the other end of the resistor to
the un-grounded end of C4712, as shown in picture1-4.

4. 4. After the above steps, we measure the voltage of
volume up signal BUTTON_VOL_UP_CONN_L. The
voltage is 1.76V. Assemble the motherboard to tester
assembly, cover the volume cable and turn on to test. We
can adjust the volume normally. Trouble is removed.