U8185
Maintenance Manual
9 Principles and Failure Analysis
Issue 1.0 (2012-03-23)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
59
Troubleshooting Process
Failure: No sound is picked up or transmitted during a call.
Figure 9-28
No sound transmitted during a call
Y
Y
N
N
Y
Y
N
N
N
N
Y
Y
N
N
Y
Y
Y
Y
N
N
No sound is transmitted
after a call is set up
Re-install the
software. Problem
solved?
End
End
End
End
Re-solder the
microphone.
Problem solved?
Is the microphone
line normal?
Is the microphone's
bias voltage 1.8 V?
Check U401
Replace the
microphone.
Problem solved?
Send the phone to an
advanced service site
for repair
Circuit Diagram Signal Summary
See section 9.4.6 "Headset."