Agilent Technologies 8719ET Service Manual page 226

Source Troubleshooting
Broadband Phase Lock Problems
3. Connect an oscilloscope to A14TP3 (CST). (Suggested vertical scale: 2.0V/div.)
4. Press
Sweep Setup
triggering on these waveforms easier.
5. If there is no signal, replace A14.
6. Use the CST signal as an external trigger for the oscilloscope and observe the signals
listed in Figure 7-4. Since these TTL signals are generated by A14 to control A13, check
them at A13 first.
The signals should look similar to the waveforms in
Table 7-3 A14-to-A13 Digital Control Signal Locations
Mnemonic
CST
L FNHOLD
FNBIAS
API1
API2
API3
API4
API5
FNLATCH
Figure 7-4 A14 TTL Signals at A14TP3
• If these signals are bad, replace A14. If the signals are bad, replace A13.
7-18
TRIGGER MENU HOLD
A13 Location
none
P2-2
P2-5
P2-32
P2-3
P2-34
P2-4
P2-35
P1-28
to stop the sweep. This will make
Figure 7-4.
A14 Location
TP3
P2-2
P2-5
P2-32
P2-3
P2-34
P2-4
P2-35
P1-58
8719ET/20ET/22ET
8719ES/20ES/22ES
RF Network Analyzers
Service Guide