HP 83522A Service Notes page 229

Model 83522A
83522A OVERALL TROUBLESHOOTING
Service
The purpose of this troubleshooting information is to provide an aid in isolating
a problem in the 83522A to a specific assembly. Further troubleshooting
information is supplied with each service sheet to isolate the problem to the
component level.
The first step in overall troubleshooting is to identify the symptom(s) and
determine under what conditions the problem exists. If the problem is an RF
plug-in error code (E001 or E050 through E053) refer to the Error Code section
of this troubleshooting procedure. Also ensure that the 8350A used with the
83522A is calibrated and functionally operating.
A failure in the 83522A normally affects one of the following functions.
Front PanelIDigital Control - Probable symptoms are error code E001,
incorrect annunciator or digit displays, inability to control operation from
front panel, or erratic instrument response to front panel entries. The
problem is generally on the Al, A2, or A3 assemblies, or with the RF Plug-
in18350A interface.
Frequency Control - Frequency control problems include frequency
inaccuracy and sweep control problems. If the 8350A VTUNE output and
power supplies are verified, the problem is most likely on the A5, A6, or A9
assemblies, or in the RF Section. If a frequency accuracy problem occurs
only during swept operation, and the inaccuracy increases with faster
sweep times, the problem is most likely with the Delay Compensation
circuit on the A7 Marker assembly.
Power Control
-
Typical problems are no W Output, maximum unleveled
RF output, or excessive power level variations. The problem is most likely
with the A4, A5, or RF Section. If the trouble is limited to power sweep and
slope control, the problem is most likely with the Power Sweep DAC on the
A5 assembly.
Marker Generation - Typical problems are that markers are generally
unstable or not present. Problem may be frequency related. Typically, the
trouble is with the A7 or A8 assemblies, or the RF Section. If problem is
with amplitude markers only, trouble may be with the A4 ALC assembly.
RF Path
-
Problems associated with high-frequency microcircuits include
spurious or harmonic distortion, no RF power, or full unleveled R F power.
For a harmonic distortion problem, refer to Section V, Adjustments. For
power problems, refer first to the A4 ALC Troubleshooting before
suspecting the RF components.
Once the problem is identified, exercise the RF plug-in to determine under what
conditions the problem exists. Some important conditions to check are:
Sweep Mode related
-
Is problem only for swept modes of operation, or
does it also exist in CW operation? If problem still exists in CW operation,
troubleshoot in this mode (it is easier to check waveforms and voltages in
CW operation).