Source Group Troubleshooting Appendix
Troubleshooting Source Problems with the Analog Bus
The analog bus can perform a variety of fast checks, However, it too is subject
to failure and thus should be tested prior to use. You should have done this in
Chapter 4, “Start Troubleshooting Here.
n
the analog bus to check
anv
one of the nodes.
Dress
I
I
lb use
: e
. . . . . .
i
.,.
~~~~~~~
.~~~~~~~~~~~.
men
press
m
~~~~~~~~~~~;~:~~~.
::::: ..::::.:
.::::::, . . . . . . .
.::::..;:
. . . . .
..-.....................-....
-
-
.._....__...
-.
L;.,:.;.:.;.:.:.;.:
.,,.
>,:L.
.,.,,
.L’.._
:.
.._
:.: . . . . .
..__
_ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .._.......
and enter the analog bus node number followed by
Lxl].
Refer to “Analog
Bus” in Chapter 10, “Service Key Menus and Error Messages”, for additional
information.
Phase Lock Diagnostic Tools
n
error messages
n
diagnostic routines
Phase Lock Error Messages
All phase lock error messages can result from improper front panel connections.
NO IF FOUND : CHECK R INPUT LEVEL means no IF was detected during pretune:
a source problem. Perform the “A4 Sampler/Mixer Check”.
NO PHASE LOCK : CHECK R INPUT LEVEL means the IF was not acquired after
pretune: a source problem. Perform the
“A4
Sampler/Mixer Check”, earlier in
this chapter.
PHASE LOCK CAL FAILED means that a calculation of prettme values was not
successful: a source or receiver failure. Perform the “Source
Prettme
Correction
Constants” routine as outlined in Chapter 3, “Adjustments and Correction
Constants” If the analyzer fails that routine, perform the
“A4
Sampler/Mixer
Check”.
PHASE LOCK LOST means that phase lock was lost or interrupted before the band
sweep ended: a source problem. Refer to “Phase Lock Diagnostic Routines”
next to access the phase lock loop diagnostic service routine. Then troubleshoot
the problem by following the procedures in this chapter.
7-38 Source Troubleshooting