U8185
Maintenance Manual
9 Principles and Failure Analysis
Issue 1.0 (2012-03-23)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
53
Figure 9-19
Volume key failure
Y
Y
N
N
Is the key damaged?
Volume key failure
Replace the
volume key FPC
Send the phone to an
advanced service site
for repair
Circuit Diagram Signal Summary
None.
9.4.3 Vibration
Figure 9-20
Circuit schematic diagram
Analysis
The vibration motor is powered by VPH_PWR and controlled by PM8029. The PM8029's
VI B_DRV_N pin functions as the drive pin of the motor. The motor is installed on a support
over the camera BTB socket. When the motor is not vibrating, VPH_PWR and VI B_DRV_N
are both at high level.
Troubleshooting Process
Failure: The motor fails to vibrate.