performance of that procedure. This level of
MAINTENANCE PHILOSOPHY
trouble clearing requires an increase in the
procedure is accessible only from previous level
[TAP-105] and uses information derived in the
The trouble-clearing TAPs provided for diagnostic
is interrupt analysis. Interrupt analysis contained in
Another method of trouble clearing that may be utilized
pack that appears on both TLP pack list and
is known as raw data analysis and describes what to do
access TOP documents at a point in trouble clearing
In many instances, access to these procedures may be
(1) ATP - First circuit pack found in interrupt
analysis should be changed. Should
this be the wrong circuit pack, probability
(2) STF - Most suspect circuit pack is the
with the same symptom. Next identified
pack should be changed at this time.
where analyzation is completed (faulty component
ALTERNATE METHODS
part is always assumed to be good and equipment used
failures are provided on three levels. The first level
The second level of trouble clearing is accessed from
the first level TAP when TLP-generated suspected faulty
equipment list has been exhausted without clearing the
any of the
ANALY: TLPFILE
TAPs which produce a
with the summary and supplemental data printed either
with or instead of the suspected faulty equipment list.
list generated from interrupt analysis.
obtained by locating procedural data provided in
Task Index List. Most DLPs are built to support TAPs
for testing both built-in and commercial hardware and
software is assumed to be good.
equipment list and provides a step-by-step procedure
for replacing circuit packs one at a time and analyzing
the results. This level is straightforward and requires
some familiarity with equipment (descriptive and theory
of circuit packs that could cause a particular interrupt.
of faulty circuits and possibly additional suspect
circuit packs not previously identified. This level of
trouble clearing is more complex and requires knowledge
of equipment, TTY techniques and printouts, and SDs, PKs,
and non-trouble analysis procedures (NTPs) with
preconditioning and system restoration steps covered
in those level procedures (TAPs, NTPs). Therefore,
access to data (DLPs) on a hunt-and-find basis is a
threat to equipment operation and may compound
trouble-clearing problems.
NULL PACK TEST GENERATED
response. This level [TAP-105]
test equipment (oscilloscopes, voltmeters, etc.).
TAP-141, TAP-142, TAP-143, or TAP-149 may produce a list
practices), TTY techniques, and diagnostic printouts.
additional knowledge and skill in the setup and use of
Prior to changing the circuit packs, diagnostics should
be run with ATP expected. If diagnostics produce:
determined) and only repair or replacement is required.
PRs, etc.
with a software generated (TLP)
suspected faulty
TAP-102, TAP-103, or TAP-104 addresses what to do
The third level of trouble clearing is signal tracing
using interactive diagnostics [TAP-106]. This
capabilities cited in the first two levels with
The more knowledgeable and experienced personnel may
problem, or it can be accessed directly from the IXL or
It is expected that this leads to an identification
is high that interrupt occurs again
TAD
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Issue 8
DEC 1995
