Tektronix WFM6100 Opt. MB, Service Manual

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General Maintenance
WFM6100, WFM7000, and WFM7100 With Option FP Service Manual
4- 11
Table 4- 4: Symptoms and causes (Cont.)
Symptom Possible sources or recommended detailed troubleshooting procedure to follow
Functional Test Failures
PVD Test Failures
In case of failure on either Functional or the Performance tests, the board at fault is
generally obvious. Before replacing a board:
1. Perform the primary and secondary power supply checks.
2. Run the advanced diagnostics and check the diagnostic log for help in isolating the
fault.
If this does not isolate the problem, then replace the Main board if the test is in one of the
following areas:
H
SDI
H
Composite
H
Ref
H
LTC
H
XGA output
H
Color Palette
H
Remote I/O
H
Ethernet
If the problem is only the SDI input, first replace the Mezzanine or Eye (depending on
option). If that does not fix the problem replace the Main board.
If the problem is Composite, replace the composite option board. If the problem persists
then replace the Main board.
If the problem is in the Audio board, perform these tests:
1. Isolating Advanced Diagnostic Lissajous errors.
2. Audio POST Failure.
Unknown Problems
Often an instrument will come into service
with vague or intermittent symptoms. In
cases like these, the following set of tests
may help find the problem or the marginal
condition.
1. Check the diagnostic log. This log records a variety of problems and will enable you
to see messages for an error that may not be currently happening.
2. Check the power supplies by performing the Primary and Secondary Supply checks.
A marginal supply can lead to intermittent operation if it is near the acceptable
threshold. This includes the main supply and the secondary supplies on each board.
3. Check the error log. This may give clues about how the unit was operating when the
user saw problems.
4. Run the functional test. This will exercise a majority of the functions in the unit and
includes the advanced diagnostics. Some parts of the test may not be necessary for
all problem areas.
5. If the unit has an Audio board, remove it and re-check any problem areas in the video
performance. The Audio board can place too much of a load on the supplies if they
are marginal. If the performance changes with the Audio board removed, then you
should perform the primary and secondary power supply checks and look for an
excess load on one of the supplies.