Huawei ETS6x8 Service Manual Troubleshooting guide
ETS668
11. Troubleshooting Guide
Huawei Technologies Co., Ltd.
Press the button PWR.
No
You should check and repair
circuit for U505, U506.
the line from BATT. power via
D500 and Q500 to Q501.
ETS668
11. Troubleshooting Guide
11.1. Troubleshooting of LOGIC Block
11.1.1. In Case of Power ON
In case of Booting Reset(repeat)
>> PAM(U202 #5(Short checking)>> change
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Can the power be conducted to #1 of U505, #4 of U506?
Yes
You should check and repair
Can 2.7V, 3V be conducted to VDD U400?
Yes
No
You should check and repair
the related and surrounded
Yes
Can it be conducted more than
3.4V to #1 for U505 and #4 for U506?
No
the U505, U506 surrounded circuit.
Yes
End
Huawei Technologies Co., Ltd.
Yes
You should check and
repair the output TCXO
signal for U400 #R15?
Yes
Yes
Yes
Yes
No
No
ETS668
11.1.2. Initial operating failure
Press the button PWR.
Can it be generated the RAM_CS1_N
signal for U400 #P14 and the ROM_CS1_N
Can it be inputted for TCXO to
U150 #36?
Can it be outputted for CHIPX8 to
U400 #A14?
Yes
No
No
You should check the
output for CLK from U301 #4
with 19.2MHz
from F300 #3 and C310.
You should check and
re-download S/W
Can it be on for LED D517?
No
You should check and
repair the related and LED.
Can it be showed the initial screen
on LCD panel normally?
You should check and
repair the related and LCD.
End
Huawei Technologies Co., Ltd.
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