Tektronix 11A32, Service Reference Manual

Page: 58 / 71

Troubleshooting
Diagnostic Troubleshooting
This section provides the information necessary lo troubleshoot a faulty instrument
to the Field Unit (FRU) level. are circuit boards, attenuator
modules, and
integrated circuits
or hybrids
that
are replaceable without soldering.
The primary means for troubleshooting is lo use the index output from
the Diagnostics or Self-Tests and cross-reference them to the suspect in the
FRU Guide tables. After an FRU is &placed, recalibration of the instrument
is normally required (this is discussed further below).
Diagnostics Overview
The processor runs a of Kernel Tests prior to the this is successful,
then the Self-Tests run to verify the functionality of each of the subsystems. Any
failure causes the instrument to
Extended Diagnostics and to display the error
index code(s) in a diagnostic Extended Diagnostics tests are a of the
Self-Tests.
The Kernel Tests and Diagnostics produce and
format
index codes differently, so they are covered separately.
Some of these tests that may indicate faulty are not run during
the Sclf-Tests (that is, errors codes are only generated by manually selecting
The next two subsections provide a quick of Kernel Tests and Extended
Diagnostics.
Kernel Diagnostics
Each time the front-panel ON/STANDBY switch is set to ON, the mainframe and
plug-ins
Kernel Tests on their microprocessor subsystems and Self-Test
Diagnostics on all of their major circuits.
After the plug-in is powered-up and the MPU has reset, the plug-in begins a se-
quence of
routines to determine if its kernel systems are operating properly. If
any of these tests fails, then it is unlikely that the plug-in can communicate failure
information to
mainframe. The flashing of a fault on the front panel CH
CH 2 indicates a particular failure. This fault code indicates which Kernel
Test is failing.
The following description explains how to read fault code:
3-22
Maintenance Service Reference