Agilent Technologies 8753ET Service Guide

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 .
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.
Phase Lock Diagnostic Routines
Perform the following steps to determine at what frequencies and bands the phase lock
problem occurs.
1. Press to
switch off the automatic phase-locked loop. Normally, when the phase-locked loop
detects lock problems, it automatically aborts the sweep and attempts to recalibrate the
pretune cycle. Switching off PLL AUTO defeats this routine.
2. Press to switch on the phase-locked loop diagnostic service mode. In
this mode, the phase lock cycle and subsweep number are displayed on the analyzer
display. (See “Service Modes Menu” on page 10-16 for more information.)
Preset System
SERVICE MENU
ANALOG BUS IN
Meas
ANALOG IN Aux Input
x1
Preset System
SERVICE MENU
SERVICE MODES
PLL AUTO OFF
PLL DIAG ON

Agilent Technologies 8753ET Specifications

General

Brand	Agilent Technologies
Model	8753ET
Category	Measuring Instruments
Language	English