U8815
Maintenance Manual
9 Principles and Failure Analysis
Issue 1.0 (2012-02-13)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
36
Figure 9-19
Analysis of the U8815 memory interface
The EMMC adopts 8-bit data cable for data transmission, and the U8815 adopts 4 GB
EMMC.
Troubleshooting Process
Failure: The handset cannot be powered on, or the power-on current is less than 100 mA.
Solution: Upgrade or reinstall the firmware of the handset, and check whether the
VREG_DCDC_2P85 voltage and peripheral components of the flash memory are normal. If
the problem persists, replace U1700.
Table 9-4 describes the signals in the circuit diagram in this section.
Table 9-4
Description of the signals in the circuit diagram in this section
Signal
Description
Reference Measurement or Wave Form
SDC3_DATA3
Data line
SDC3_DATA2
Data line
SDC3_DATA1
Data line
SDC3_DATA0
Data line
SDC3_DATA7
Data line
SDC3_DATA6
Data line
SDC3_DATA5
Data line
SDC3_DATA4
Data line
SDC3_CLK
Clock