AR 100A400AM20, Руководство по эксплуатации и обслуживанию

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Model 100A400AM20
24 Rev A
4.3 TROUBLESHOOTING
CAUTION:
The transistors used in the Model 100A400AM20 amplifier are GaN
HEMT and LDMOS. These devices are very reliable when installed in a
suitable circuit, but they can be easily damaged by improper
troubleshooting or handling techniques.
The gate junctions of the GaN HEMTs have a high input impedance and
are susceptible to static damage or damage due to the use of an
ungrounded soldering iron. Do not try to check the GaN HEMTs with an
ohmmeter.
Use caution when troubleshooting the GaN HEMTs; do not short the gate
to the ground or to the drain.
CAUTION:
Use care when unpacking new transistors. The transistors’ packaging
should only be opened at Electrostatic Discharge (ESD)-approved
workstations, by individuals who are familiar with the handling of
microwave GaN HEMTs, LDMOS and other ESD-sensitive devices.
Troubleshooting the Model 100A400AM20 in a logical manner can speed the solution to a problem. The
settings of potentiometers (pots), capacitors (caps), or other variables should not be disturbed until other
problems have been eliminated. Comparing the measured DC voltages to those shown on the schematics can
solve many problems. Before measuring circuit voltages, first verify that the voltages to the circuits are
correct.
Model 100A400AM20 troubleshooting symptoms and remedies are described in the sections that follow

4.3.1—Power On Indication Doesn’t Display on Front Panel Vacuum Fluorescent Display (VFD) when
POWER Switch is Depressed

4.3.2—The Unit Cannot be Operated Remotely

4.3.3—Thermal Fault

4.3.4—Interlock Fault

4.3.5—PS2 (Power Supply) Fault

4.3.6—Amplifier Faults

4.3.7—Low or No Power Output (DC Tests)

4.3.8—Low or No Power Output (RF Test)