Huawei Y300 Maintenance Manual page 74

Y300 Maintenance Manual
Figure 9-48 Troubleshooting process when the Y300 fails to detect the USIM/SIM card
Circuit Symbols
The PM8029's MPP pin converts the level for the PM8029 to connect to the SIM card.
The level VREG_L16_UIM1 ranges from 1.5 V to 3.05 V. The operating level of the USIM
card port is 1.8 V or 3.0 V. Table 9-4 lists interface signals provided by the PM8029 for
converting the USIM card level.
Table 9-4
Interface Signal
Between the PM8029
and MSM8225
N/A
UIM1_MSM_CLK
UIM1_MSM_DATA
Issue 1.0 (2013-01-24)
The Y300 fails to detect
the UIM card.
Can the Y300
detect the UIM
card after the UIM
card is replaced?
N
Is the UIM card
slot normal?
Y
Is the VEEG_L16_USIM1
normal?
Y
Return the Y300 to Huawei for
repair.
NOTE
The TVS is used to provide the ESD and surge protection due to a large number of SIM card operations.
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Copyright © Huawei Technologies Co., Ltd.
Y
End
N
Re-solder or replace
the UIM card slot.
Level Interface Signal
Between the
PM8029 and USIM
Card
UIM1_RESET
VREG_S3
UIM1_CLK
UIM1_DATA
9 Principles and Failure Analysis
Check the
VEEG_L16_USIM1.
Level
VREG_L16_UIM1
(Set using the Y300's
software)
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