HP 8560A

Table 10-4. 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
Check A14J301 10 MHz REF Input
2heck Al5 RF Assembly
Check Current Source U307
Check FM Loop Sense
Check YTF Gain and OFFset DACs
Check Level at Amplifier Input
Check Levels into Mixer U400
Check Loop References
Check Main Coil Tune DAC
Check Main Coil Coarse and Fine DACs
Check Main Roller Mixer
Check Main Roller Oscillator and Output Buffer
Amp
Check Main Roller PLL
Check Main Roller Pretune DAC
Clheck Main Roller Sweep/Hold Switches
Check Offset Oscillator and Buffer Amp
Manual Procedure to Perform
Confirming a Faulty Synthesizer Section
(steps 9-11)
Unlocked YTO PLL (steps 10-13)
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 l-4j
Confirming a Faulty Synthesizer Section
(steps 12-l 7)
Confirming a Faulty Synthesizer Section
(steps 5-8)
Confirming a Faulty Synthesizer Section
(steps 18-25)
First LO Span Problems (All Spans) (steps l4-21)
Unlocked YTO PLL (steps 28-34)
YTF Driver Circuit (steps 10-23)
Third LO Driver Amplifier (steps l-6)
Unlocked Offset PLL (steps 3-13)
Unlocked Offset PLL (steps 1 and 2)
Unlocked YTO PLL (steps 45-49)
Unlocked YTO PLL (steps 41-44)
Main Oscillator PLL (steps 10-15)
Main Oscillator PLL (steps l-4)
Main Oscillator PLL (steps 16-22)
Main Oscillator PLL (steps 5-9)
First LO Span Problems 21 MHz (step 9)
Offset Oscillator PLL (steps 1-3)
Synthesizer Section 10-9