Agilent Technologies 89410A Service Manual page 81

the source sine wave at the failing values. If the signal is
incorrect, go to Step 7.
f Set the oscilloscope to 600 mV/div.
g
Press the following keys:
[DC offset ]
[ Marker/Entry ]
h Rotate the RPG knob while monitoring the oscilloscope. The sine
wave dc offset value should change from +1 V to -1 V as the RPG
knob is turned.
To keep the sine wave displayed, adjust the oscilloscope's trigger
level while varying the dc offset value.
i If the dc offset function operates correctly, go to Step 3.
2 Check the DC offset control signals.
a
Place the analyzer on the side closest to the display.
b
Remove the bottom cover.
c Press the following keys:
]
[Preset
[ Source ]
[ source on]
]
[DC offset
[ ]
Marker/Entry
d Using a logic probe, check the TTL signals listed in the following
table while rotating the RPG knob. The signals should toggle as
the dc offset is varied from minimum to maximum.
Troubleshooting the Analyzer
To troubleshoot source and calibrator out failures
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