XIEGU
Product Maintenance Manual G90/G90S Portable Short-Wave Transceiver
XIEGU All Rights Reserved Version No.: 1.0 2022-07 Page
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Fault phenomenon: It cannot be written into Bootloader or the application
Fault phenomenon: high current
Fault
Phenomenon
Maintenance Method
Display
Checkpoint
Failure to burn
program
Check whether the voltage
is 3.3V
C
Check whether the MCU is
faultily welded
B
Check whether the pedestal
is faultily welded
D
Fault
Phenomenon
Maintenance Method
Display
Checkpoint
High current and
hot MCU
Check whether the voltage
is 3.3V
C
If the voltage at point C > 3.3V, the LDO regulator has already
been damaged. It is necessary to replace the LM1117-3.3
regulator first, confirm that the output voltage is 3.3V, and then
replace the damaged MCU. Otherwise, it will cause a secondary
fault to burn the MCU.
During the maintenance, it has ever been found that the short
circuit of the display FPC pedestal welding lead to the 3.3V
grounding short circuit, where attention to check is thus required.