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S7-PRO Maintenance Manual (Basic Version V2.1)
INTERNAL
2012-07-20
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
Page 52 of 97
Charging fails
Check whether the voltage
difference among D3, D20, C747,
C486, and C108 is 5 V
Measure the R4 voltage
difference and check for improper
SMT
Solder R4
No
Yes
Yes
Replace D3, D20, C747,
C486, and C108
Replace U48
No
9.4 Failure to Identify SIM Card
Diagram of the circuits:
The SIM_CD indicates the PIN of the SIM card and is used for identifying the SIM card.
When the SIM card is inserted, the voltage of SIM_CD changes from a high level to a low
level.
Remark: For the maintenance procedures, see Appendix 1 (diagram of PRO components).
Perform the eMMC programming again (U12).