Agilent N5161A/62A/81A/82A/83A MXG Signal Generators Service Guide
Troubleshooting
Troubleshooting Assembly Level Problems
1-26
e.
Press
AMPTD
>
ALC On
.
8.
Account for the attenuated output signal from the generator. The spectrum analyzer should be displaying a CW signal with an amplitude
of > 18 dBm.
a.
If the signal generators’s output level is < +18dBm, replace the A3 RF Assembly.
b.
If the signal generator’s output level is > +18dBm, continue to step 9.
9.
Repeat steps 6 through 8, but change the spectrum analyzer and signal generator’s frequencies to 1GHz, 2.5 GHz, and 3.199 GHz
•
If the power level is good at all frequencies, replace the A7 Micro Deck.
•
If the power level is not good at all frequencies, replace the A3 RF Deck.
NOTE
At 3.2 GHz the signal generator’s CW signal will not be present.
Troubleshooting Assembly Level Problems
WARNING
To allow the power supplies to discharge, wait 30 seconds after unplugging the instrument before removing or
installing any assemblies.
CAUTION
Before removing any instrument assembly, the instrument’s static and dynamic arrays must be configured for the exchange of
assemblies. The process to do the appropriate configuration is performed automatically by the MXG with the
Installation and Removal Overview
front panel softkeys. Refer to the
Assembly Installation and Removal Overview
the
“Hardware Assembly Installation and Removal Softkeys” on page 4-2
A1 Power Supply
The A1 Power Supply is a switching supply with a switching frequency of 120 kHz. It operates from 88 RMS Vac to 269 Vac, at line
frequencies of 45 Hz to approximately 400 Hz. The A1 Power Supply is designed with an automatic line-voltage and frequency selection.
Except for the 5.1V standby, all power supply outputs are over-current protected and will not be damaged by a continuous short circuit.
1.
Remove the outer and inner instrument covers. Refer to
Chapter 3, "Assembly Replacement"
for instructions on removing the
instrument covers.
2.
Reconnect the power cord.
3.
Position the signal generator so the A3 RF assembly faces up.
4.
Measure the voltage levels at A3J10.
Refer to
to determine the correct supply voltages for the signal generator’s power supplies. Because the power supply voltages
are filtered or regulated on the A3 RF assembly, the faulty assembly could be either the A1 Power Supply or the A3 RF assembly.
5.
If any voltage is incorrect, replace the A1 Power Supply.
NOTE
If all A3J10 voltages are 0, the most likely cause is the internal power line fuse in the A1 Power Supply. The internal power line
fuse is NOT replaceable on its own. The whole A1 Power Supply must be replaced.
6.
Re-measure the voltage levels at A3J10.
7.
If the voltages are still incorrect, the faulty assembly is the A3 RF assembly and not the A1 Power Supply. Replace the A3 RF assembly.
If you replaced the A1 Power Supply, but the A3 RF assembly was the faulty assembly, you can return the new A1 Power Supply to
Agilent.
深圳德标仪器
135-1095-0799