Specifications

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Troubleshooting
Troubleshooting Assembly–Level Problems
705 F/2 Test
1. Using an oscilloscope, check the 10 MHz Synthesis line on P33–15. The signal period should be
100 ns with an amplitude of approximately 3V
pp
.
• If the signal is good, replace the A6 Frac–N.
2. If the signal is bad, turn the signal generator power off, remove the A6 Frac–N, and measure
P33–15 again.
• If the signal is good, replace the A6 Frac–N.
3. If the signal is still bad, measure P41–5 on the A7 Reference.
• If the signal is good at P41–5, replace the A31 Motherboard.
• If the signal is bad at P41–5, replace the A7 Reference.
706 FM Path Test
1. Using an oscilloscope, check P31–22 (FM_On_H):
a. Loop self–test 706
b. Check for a TTL transition from 0 Vdc to +5 Vdc.
• If the signal is not present, refer to A5 Sampler troubleshooting.
2. If the signal is present, check P31–11 (FM):
a. Loop self–test 706.
b. Check for a 0 to 3.3 Vdc transition.
• If the signals is present, replace the A6 Frac–N.
• If the signal is not present, refer to A11 Pulse/Analog Modulation Generator
troubleshooting.
707 Sweep Phase Detector Test
1. Replace the A6 Frac–N.