To Troubleshoot Trigger Failures - Agilent Technologies 89410A Service Manual

To troubleshoot trigger failures

Use this test when the trigger function is suspected of failing and the
following self tests passed:
1
Digital Source
Digital Filter
ADC
Check the trigger calibration signal.
a
Set the power switch to on (
b When the power-up tests are finished, press the following keys:
]
[
Preset
[
System Utility ]
[ auto cal off ]
]
[
more cal setup
[
]
auto zero cal off
]
[
Return
[ ]
more
[ ]
diagnostics
[ ]
service functions
1125
[ ]
enter
[ ]
special test modes
[ ]
cal
[
]
cal signal on
c Place the analyzer on the side closest to the display.
d
Remove the bottom cover.
e
Set the oscilloscope as follows:
CH1 V/div
Input Impedance
CH1 Coupling
Time/div
Probe Atten
f
Using a high impedance 1:1 oscilloscope probe, check that A91 J6
pin 25B is a 1±0.1 Vp-p square wave.
g If the signal is incorrect, the A35 Analog Source assembly is
probably faulty.
h
Return the analyzer to its normal position.
To troubleshoot trigger failures
l ).
200 mV/div
Ω
1 M
dc
500 ns/div
1
Troubleshooting the Analyzer
1-83