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Model 1U1000
4.3
TROUBLESHOOTING
Troubleshooting the 1U1000 in a logical manner can speed the solution to a problem. The settings of pots,
capacitors or other variables should not be disturbed until other problems have been eliminated. Many problems
can be solved by comparing the measured DC voltage to those shown on the schematics. Before measuring
circuit voltages, first verify that the voltage to the circuits are correct.
Model 1U1000 troubleshooting symptoms and remedies are described in the sections that follow:
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Section 4.3.1–Green Power Indicator LED Doesn't Light
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Section 4.3.2–Low or No RF Power Output (DC Test)
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Section 4.3.3− Low or No RF Power Output (RF Test)
4.3.1
Green Power Indicator LED Doesn't Light
Refer to Schematic Number 10043990.
1. Is the cooling fan running?
2. If the fan is not running, check to see that the 1U1000 is plugged into a live outlet. Check the line cord, is
the line cord plugged into the 1U1000 completely?
3. Check the AC fuse located in the AC receptacle on the rear panel.
4. Check the output voltage from PS1, there should be +15VDC, -15VDC and +5VDC.
5. If there is no output:
•
Check the AC input to PS1. The AC input should be equal to the AC Line Voltage. If there isn't any
AC input, the power switch could be defective or there could be an open in the wiring or other
component.
•
Check the fuse on the AC input located in PS1, if okay, remove the output connector from PS2, recheck
the D.C. output voltage, if voltage is present without load, there may be a short on the output of PS1.
10
The RF transistor used in the 2.5U1000 amplifier is a GaN FET. This device
is very reliable when installed in a suitable circuit but can be easily
damaged with improper troubleshooting or handling techniques. The gate
junctions of the GaN FET have a high input impedance and are susceptible
to static damage or damage due to an ungrounded soldering iron. Do not
try to check FET's with an ohmmeter. Use caution when troubleshooting;
do not short the gate to ground or to the drains.
Use care when unpacking new FET's. The FET packaging should only be
opened at static approved work stations, by individuals familiar with the
handling of static sensitive RF GN FET's.
CAUTION:
CAUTION:
Rev A
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