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: startup failure, unable to connect with the machine head (mainboard MCU
indicator light flashes slowly and is always on)
Maintenance methods:
The main manifestations of such faults are as follows:
After starting up, the blue indicator light beside the main MCU
flashes slowly or is always on.
After starting up, the level on the machine head display is
-256dBm, and there is no waterfall plot.
Maintenance methods:
Fault
Phenomenon
Maintenance Method
Small signal board
Checkpoint
Startup failure
Check whether there is false
welding of components
IC1
Check whether there is false
welding of components
IC2
Check whether there is false
welding of components
IC3
Check whether there is false
welding of components
IC4
Check whether there is false
welding of components
A10
Check whether the two diodes
are broken down
A11
According to previous maintenance experience, there is a higher
chance of false welding of IC3, which shall be checked
emphatically.
Principle: IC1, IC2, IC3 and IC4 are for IIC bus communication.
When there is a problem in the bus communication of a chip, the
communication mechanism will give up the correspondence with
it after a certain time and change to communicate with other
remaining chips.
The phenomenon
when such actions occur:
After starting up, the indicator light is always on, and then
starts flashing after about 10 seconds. At the same time, the
sound of relay operation is heard, and background noise of
the horn starts.
Special attention:
There is a higher defect rate of domestic GD32F450 series chips
(about 4%), causing a lot of failures such as startup failure or
connection failure with the machine head.
