Tektronix LTA7P Series, Service Manual

Page: 139 / 172

Troubleshooting
TLA7Nx, TLA7Px, & TLA7Qx Logic Analyzer Module Service Manual
6- 31
If the fault is that the logic analyzer module acquires no data or faulty data, the
probe may be at fault. Perform the following procedure to isolate such faults to a
probe or to the logic analyzer module.
NOTE
. The procedure below requires that the logic analyzer is functional and
operates normally when the modules are installed. Procedures to functionally
verify the probes are located in the probe manual.
1. Verify that the probe is correctly connected to the module and to the
system-under-test; check for loose or disconnected probe channels.
2.
Move the suspected probe to another probe connector and observe if the
problem follows the probe. If the problem does not follow the probe, the
module may be faulty.
3. Substitute the suspected probe with a known good probe and observe if the
problem is still present. If the problem still occurs, the module may be
faulty. Refer to
Troubleshoot the Logic Analyzer Module to isolate the
problems within that module.
4. If you have determined that the probe is faulty, try to isolate the problem to
an individual channel. A faulty channel may indicate a faulty probe podlet.
Isolate faulty podlets by switching single podlets and observing if the
problem tracks with the suspected podlet. Refer to the instructions in the
probe manual for replacing faulty probe podlets.
Troubleshoot the Logic Analyzer Module
Follow the procedure in this section to identify the failed part within the logic
analyzer module.
This procedure requires that the module is installed in a fully functional
mainframe. If you have not determined that the mainframe is functional, or if
you suspect the problem might be in a probe or in another module, refer to
Eliminating Other Problem Sources .
The basic troubleshooting procedures require minimal test equipment. There are
no accessible test points to measure voltages. An ohmmeter is recommended for
checking fuses.
The fault isolation procedure requires that you:
H
recognize codes flashed by the front-panel LEDs during power up
H
are familiar with the power-on diagnostics
Probe-Level Troubleshooting
Equipment Required
Preparation