Huawei Ascend Maintenance Manual page 37

Y210 Mobile Phone
Maintenance Manual
Before starting the following process, ensure that the USIM card and the antenna are well
connected.
Figure 9-7 GSM/DCS transmission failure
Table 9-3 and Table 9-4 describe the working status of the GSM/DCS power amplifier U3501.
Table 9-3 U3501 working status (1)
GSM_PA_EN
H
L
Table 9-4 U3501 working status (2)
GSM_PA_BAND
L
H
Issue 1.0 (2012-11-28)
GSM/DCS transmission
failure
When the RF cable is not
inserted, are J3204's pin
1 and pin 2 connected?
Y
Are U3201's control signals
normal?
Y
Are U3501's GSM output
and DCS output
approximately 33 dBm and
30 dBm respectively?
Y
Do U3801's pin A10 and pin
Y
A9 have output?
Y
Check U401
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9 Principles and Failure Analysis
N
Check J3204
N
Check U3201 and
U401
N
Check U3501
N
Check U3801
PA
ON
OFF
Mode
GSM850/900
DCS1800/1900
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