HP 8560A, Service Manual

Page: 353 / 450

Table Automatic Fault isolation References (1 of 2)
Suspected Circuit Indicated
by Automatic Fault Isolation
Check the YTO Loop
Check 1st LO
Check 1st LO Pretune Frequency and Amplitude
Check 3rd LO Drive
Check 10 MHz Reference to Phase Frequency
Detector
Check for 10 MHz Signal at Other Input to
Phase/Frequency Detector
Check A3 ADC MUX function block
Check Al4 Frequency Control Assembly
10 MHz REF Input
Al5 RF Assembly
Current Source
FM Loop Sense
YTF Gain and
Check Level at Amplifier Input
Check Levels into Mixer
Check Loop References
Check Main Coil Tune DAC
Check Main Coil Coarse and Fine
Check Main Roller Mixer
Check Main Roller Oscillator and Output Buffer
Main Roller PLL
Main Roller Pretune DAC
Main Roller Sweep/Hold Switches
Offset Oscillator and Buffer Amp
Manual Procedure to Perform
Confirming a Faulty Synthesizer Section
(steps 9-11)
Unlocked YTO PLL
(steps
Third LO Driver amplifier
(steps l-6)
Unlocked Reference PLL
(steps 8-13)
Unlocked Reference PLL
(steps 12 and 13)
Confirming a Faulty Synthesizer Section
(steps
Confirming a Faulty Synthesizer Section
(steps 12-l
Confirming a Faulty Synthesizer Section
(steps 5-8)
Confirming a Faulty Synthesizer Section
(steps 18-25)
First LO Span Problems (All Spans)
(steps
Unlocked YTO PLL
(steps
YTF Driver Circuit
(steps
Third LO Driver Amplifier
(steps l-6)
Unlocked Offset PLL
(steps
Unlocked Offset PLL
(steps and 2)
Unlocked YTO PLL
(steps
Unlocked YTO PLL
(steps
41-44)
Main Oscillator PLL
(steps
Main Oscillator PLL
(steps
l-4)
Main Oscillator PLL
(steps
Main Oscillator PLL
(steps 5-9)
First LO Span Problems MHz
(step 9)
Offset Oscillator PLL
(steps 1-3)
Synthesizer Section 10-9