Huawei Y300 Maintenance Manual page 57

Y300 Maintenance Manual
Figure 9-29 Troubleshooting process when the Y300 fails to transmit signals
If the WCDMA 850 MHz or 900 MHz transmit channel is abnormal, check U3401 instead of
U3302 in the preceding flowchart.
If the WCDMA 1900 MHz transmit channel is abnormal, check U4202 instead of U3302 in
the preceding flowchart.
If the GSM 900 MHz or 1800 MHz transmit channel is abnormal, check U3501 instead of
U3302 in the preceding flowchart.
Issue 1.0 (2013-01-24)
The WCDMA 2100 MHz
transmit channel is faulty.
Check U3201 before the RF
cable is connected.
Are pin 1 and pin 2
of U3201 properly
connected?
Y
Are the control signals of the
U3202
normal? (See Table 9-2
for the truth table.)
Y
Is the WCDMA 2100 MHz PA
output of U3302 normal?
Y
Are I/Q signals and power
voltage of U3801 normal?
Y
Y
Check the U401.
End
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9 Principles and Failure Analysis
N
Check the U3201.
N
Check the U3202
and U401.
N
Check the U3302.
N
Check the U3801.
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