Technical data

7-30 Chapter 7
Source Troubleshooting
Source Group Troubleshooting Appendix
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.”
To use the analog bus to check any one of the nodes, press
. Then press
and enter the analog bus node number
followed by . Refer to “Analog Bus” on page 10-20 for additional information.
Phase Lock Diagnostic Tools
• error messages
• 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” on page 7-8.
NO PHASE LOCK: CHECK R INPUT LEVEL means the IF was not acquired after pretune: a
source problem. Perform the “A4 Sampler/Mixer Check” on page 7-8.
PHASE LOCK CAL FAILED means that a calculation of pretune values was not successful: a
source or receiver failure. Perform “Source Pretune Correction Constants (Test 48)” on
page 3-10. If the analyzer fails that routine, perform the “A4 Sampler/Mixer Check” on
page 7-8.
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.
Preset System
SERVICE MENU ANALOG BUS IN
Meas
S PARAMETERS
S PARAMETERS ANALOG IN Aux Input
x1