Clock Circuit - Huawei U8860 Maintenance Manual

U8860
Maintenance Manual

9.2.3 Clock Circuit

Clock
VCTCXO in 19.2 MHz
Issue 1.0 (2011-11-14)
Charging failure
Is J1502 cold soldered,
damaged or distorted?
N
Is the voltage of J1502 Pin1
about 5 V?
Y
Is F1501 connected.
Y
Is the Q301 pin voltage Vs (Pin2)
approximate to Vd (Pin3).
Y
Is the output voltage of the charging
IC 3.7V-4.2V.
Y
Replace U301.
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Y
Replace J1502.
N
Replace J1502.
N
Replace F1501.
N
Replace Q301.
N
Replace U1001.
Effect
Supporting master clock for the
MSM8255
9 Principles and Troubleshooting
Remarks
39