Tektronix TLA Series, Service Manual

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Troubleshooting
6- 28
TLA Series Digitizing Oscilloscope Modules Service Manual
The test equipment needed to troubleshoot the DSO module depends on the type
of failure. Many faults can be detected using a digital multimeter. Testing and
adjustments might be required to correct some faults. Under those circumstances,
you will need the test equipment listed in the
Performance Verification chapter.
The fault isolation procedure requires that you:
H
recognize codes flashed by the front-panel LEDs during power up.
H
be familiar with the power-on diagnostics.
H
know how to run extended diagnostics and self calibration.
Front-Panel LEDs. The READY, ARM’D, and TRIG’D front-panel LEDs provide
information about the DSO module at power on. You will use these indicators
while performing the Fault Isolation Procedure. LED behavior follows:
H
Under normal conditions, the ARM’D and TRIG’D indicators light for a
short time after power is turned on. Approximately five seconds after
power-on, the READY indicator turns on and the remaining indicators may
turn off.
H
The green READY LED indicates that the module has passed the power-on
diagnostics and is ready to communicate with the controller.
Self Calibration.
Use the self calibration to calibrate the installed modules. Run
the self calibration after a minimum of a 30 minute warm-up.
Power On Diagnostics. Power-on diagnostics check basic functionality of the
DSO module at every power-on. If any failures occur at power on, the screen
displays the calibration and diagnostics property sheet. The power-on diagnostics
page shows a list of the diagnostic tests with a Pass or Fail indication for each
board in the module.
NOTE
. If there are no diagnostic failures when you power on the instrument, you
can display and run the calibration and diagnostics property sheet by selecting
Calibration and Diagnostics from the System menu.
Equipment Required
Preparation