Tektronix WFM700 Series, Service Manual

Page: 162 / 194

Troubleshooting
4- 28
WFM700 Series Waveform Monitors Service Manual
Table 4- 4: Failure symptoms and possible causes (cont.)
Symptom Possible cause(s)
Instrument locks up
H
Power down the instrument, then restart.
H
Replace the CPU circuit board.
Power Up Diagnostic errors
Internal Digital Path Diagnostic
errors
Audio Path Diagnostics
Use the Diagnostics Error Troubleshooting Tree on page
4--39.
Modules not recognized
H
Module firmware incompatible with mainframe
software version.
H
Module not fully installed into the slot.
H
Faulty module.
Mainframe powers on but no signal
displayed
H
Wrong slot selected, wrong input selected.
H
Module not fully installed into the slot.
Front panel buttons don’t operate
correctly.
Touch panel doesn’t operate
correctly.
Use the Front Panel Buttons and Touch Panel
Troubleshooting Tree on page 4--38.
Performance requirement not met as
tested with the Performance Verifica-
tion procedures. Perform the procedures located in the Adjustments
chapter.
One (or any combination) of the
following functions fail to perform:
WFM
VECTOR
PICTURE
GAMUT
MEASURE
Real Time Display module faulty.
Spurious gamut errors
H
Poor quality input signal.
H
Perform the Digital Signal Path Diagnostics.
Failure to lock to external reference
signal
H
Verify the reference input signal is of the proper type
as listed in the User manual.
H
External Reference module faulty.
G/Y, B/Pb, R/Pr output signals
correct but not at the VGA PIX MON
connector Check the ribbon cable connections on the External
Reference module between the two circuit boards at J1
and J270.
INPUT A or INPUT B work but not
both Faulty Input Module.
HD or SD waveform work but not
both Faulty Input Module.