Tektronix WVR6020 Service Manual

General Maintenance
Table 4-4: Symptoms and causes (cont.)
Symptom Possible sources or recommended detailed troublesho oting procedure to follow
Functional Test Failures
PVD Test Failures
In case of failure on e ither 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:
SDI
Composite
Ref
LTC
XGA output
Color Palette
Remote I/O
Ethernet
If the problem is in the audio board, perform these tests:
3. Isolating Advanced Diagnostic Lissajous errors.
4. 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 P rimary 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 c lues about how the unit was operating when
the user saw problems.
4. Run the functional test. This w ill 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.
4–10 WVR6020, WVR7020, and WVR7120 Waveform Rasterizers Service Manual

Tektronix WVR6020 Specifications

General

Brand	Tektronix
Model	WVR6020
Category	Measuring Instruments
Language	English