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A1018s/A1018sc Standard Electrical Repair
4/00021-2/FEA 209 544/16.B
19
(42)
4.7 Both the handsfree microphone and the
handsfree speaker is out of order.
Make sure the system connector is okay and not dirty.
Open the phone and check for liquid damages, especially around the pads of the
system connector. If necessary, use alcohol and a brush to clean.
Measure the resistance between J602:3 (fig. 4.3) and R635 (~0 Ohm at one side, the
resistance of the resistor is 22 kOhm, fig. 4.1).
Measure the resistance between J602:5 (fig. 4.3) and R636 (~0 Ohm at one side, the
resistance of the resistor is 22 kOhm, fig. 4.1).
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If any of R635 or R636 is incorrect, replace them.
•
If the resistance is too high, is there a foil damage and the board has to be dis-
carded.
Measure the resistance of R601 and R605 (both 1 kOhm, class A, fig. 4.1).
•
If all resistances are correct, check the soldering at N800 and D600:67,70 (fig.
4.2).
If the fault still remains, send the phone to the next repair level.
4.8 Mute fault.
Connect a call and measure the voltage between AGND of the system connector,
J602:4 (fig. 4.5) and MUTE, J602:6, it should be 3.2 V during a connected call.
•
If the voltage exists, the fault probably is in the handsfree unit.
•
If the voltage doesn´t exists, open the phone and check for liquid damages, espe-
cially around the pads of the system connector.