A1018s/A1018sc Standard Electrical Repair
4/00021-2/FEA 209 544/16.B
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(42)
4 Audiofel
4.1 Type of fault.
Make a call from the phone that is to be tested (later called the phone) to a phone
that is working correctly (later called the reference phone).
Check the function of the microphone and the earphone.
Connect a handsfree unit to the system connector of the phone.
Check the function of the phone’s external connections by listening to the external
speaker/earphone when talking in the reference phone and by listening to the ear-
phone of the reference phone when talking in the external microphone of the phone.
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If there is low or no sound in the earphone of the phone, proceed to section 4.2.
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If both the earphone and the handsfree speaker don’t work, send the phone to the
next level.
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If the sensitivity of the microphone is low (low or no sound in the reference
phone), proceed to section 4.3.
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If both the microphone in the phone and the microphone of the handsfree don’t
work, send the phone to the next level.
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If both the microphone and the earphone don’t work, proceed to section 4.4.
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If the microphone, the earphone and the handsfree don’t work, send the phone to
the next level.
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If the microphone of the handsfree doesn’t work, proceed to section 4.5.
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If the speaker of the handsfree doesn’t work, proceed to section 4.6.
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If both the microphone and the speaker of the handsfree don’t work, proceed to
section 4.7.
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If the phone sounds strange (the sound is distorted, scrambled, full of static or
“chopped”), send the phone to the next level.
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If the phone isn’t able to mute a car stereo through a car mounted handsfree (the
mute signal doesn’t work), proceed to section 4.8.
4.2 Earphone out of order.
Open the phone and check for liquid damages.
Most of the earphone faults are mechanical. Therefore you should start with replac-
ing the front (with the earphone) to one you know works and try again.
If the fault remains, make sure the earphone connector (J810, fig. 4.1) is intact and
correctly soldered.
Check the soldering at N800 (fig. 4.2).
Measure the resistance between the pins of J810 (>1 MOhm).
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If it is too low, replace C842 (class A, fig. 4.1)