Agilent Technologies 35670A Service Manual page 226

Troubleshooting the Analyzer
To troubleshoot source and calibrator failures
Step 5. Check the Input assembly.
❑
• Using an oscilloscope and a 10:1 probe, check the following signal.
Oscilloscope Setup
Connect CH1 to A1/A2 TP 300
CH1 V/div 200 mV/div
Input
Ω
1 M
Impedance
dc
CH1 Coupling
10
Probe Atten
Repetitive
Display Mode
8
Averaging
20 ms/div
Time/div
Trg'd Sweep
Trigger
Chan1
Trig Src
• If the signal is incorrect, the A1/A2 Input assembly is probably faulty.
Step 6. Compare the analyzer's self-test results to the following table.
❑
• Press the following keys:
[ ]
System Utility
[ ]
MORE
[ ]
SELF TEST
[
FUNCTIONL TESTS
[
DIGITAL PROCESSOR
[ ]
ALL
[ ]
Rtn
[
ADC GATE ARRAY
• Determine the probable faulty assembly by comparing the analyzer's
self-test results to the following table.
Self-Test Results
Trigger Gate Array fails and ADC Gate Array passes
Baseband fails, Zoom fails, and ADC Gate Array passes
ADC Gate Array fails
All self tests pass through the ADC Gate Array
This test does not check all the signals from the A6 Digital assembly to the A5 Analog
and A1/A2 Input assemblies. All the functions of the A6 Digital assembly are checked
by the self tests except for a few output buffers. If replacing the A5 Analog assembly
does not fix the failure, the A6 Digital assembly is probably faulty.
4-50
Parameters
Amplitude
Time
Distortion
]
]
]
Agilent 35670A
Waveform
Channel 1 Output
Probable Faulty Assembly
A6 Digital
A6 Digital
A5 Analog
A5 Analog