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Model 5U1000
Troubleshooting the 5U1000 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 5U1000 troubleshooting symptoms and remedies are described in the sections that follow:
•
Section 4.3.1–Green Power Indicator LED Doesn't Light
•
Section 4.3.2–Low or No RF Power Output (DC Test)
•
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 10044273.
1. Is the cooling fan running?
2. If the fan is not running, check to see that the 5U1000 is plugged into a live outlet. Check the line cord, is
the line cord plugged into the 5U1000 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 DC output voltage, if voltage is present without load, there may be a short on the output of PS1.
4.3.2
Low or No RF Power Output (DC Test)
If the power indicator is lit (green):
1. Check the position of the RF gain control.
2. Check the RF input power to the 5U1000, is it the correct frequency range and amplitude.
3. Check the RF output connections, is it correctly connected to the load? Is the coax cable defective?
4. Check the following voltages on the Power Supplies. If any of the voltages are out of tolerance, correct the
problem before further troubleshooting.
P2-1
+5V
P2-2
+5V
+15V ±0.4V
P2-5
P2-8
-15V
10
±0.4V
P3-1
±0.3V
±0.4V
+30V ±0.4V
Rev A
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