Table 11-2. Automatic Fault Isolation References (continued)
Suspected Circuit Indicated
by Automatic Fault Isolation
Manual Procedure to Perform
Check offset span accuracy
Check phase/frequency detector
Check path to phase/frequency detector
Check sampler drive output of A7
Check sampler IF
Check sampler/sampler IF operation
Check span attenuator
Check sweep generator
Check sweep + tune multiplier
Check the 600 MHz reference loop amplifier
Check the YTO loop
Check YTO FM coil driver
Check YTO FM coil driver and main loop
error voltage driver
First LO Span Problems
52
MHz (step
8)
Unlocked Reference PLL (steps
17-22)
Unlocked Offset PLL (steps 3-7,
14-f9)
Unlocked YTO PLL (steps
18-21)
Unlocked YTO PLL (steps
22-26)
Sampler and Sampler IF (steps l-15)
First LO Span Problems (All Spans) (steps 6-13)
Sweep Generator Circuit
YTF Driver Circuit (steps 4-9)
Unlocked Reference PLL (steps 23-26)
Unlocked YTO PLL
First LO Span Problems (2.01 MHz to 20 MHz)
(Step
6)
Unlocked YTO PLL (steps
3540)
Synthesizer Section
1
l-5
