Tektronix TLA Series, Service Manual

Page: 107 / 130

Troubleshooting
TLA Series Digitizing Oscilloscope Modules Service Manual
6- 29
Extended Diagnostics.
The extended diagnostics execute more thorough tests than
the power-on diagnostics. Using the extended diagnostics, you can do the
following tasks:
H
Run test individually or as a group
H
Run tests once or continuous
H
Run tests until a failure occurs
While the test are executing, the word Running displays adjacent to the test.
When the tests are complete, the tests display either a Pass or Fail indication.
This section contains two troubleshooting charts that will help you locate faulty
DSO module circuit boards:
H
The Primary Troubleshooting Procedure chart on page 6--30 provides
troubleshooting steps that test the DSO module circuit boards
H
The Power Supply Troubleshooting Procedure chart on page 6--31 locates
power supply faults within the DSO module
1.
Install the DSO module into a mainframe.
2.
Before you power on the mainframe, watch the READY, ARM’D, and
TRIG’D front panel indicators.
3.
Power on the mainframe and note how the front panel indicators respond.
4.
Use the Primary Troubleshooting Procedure chart on page 6--30 to determine
how to proceed.
5.
If diagnostic failures occur, the tree will refer you to Table 6--6 on page
6--33. Using that table, you can correlate the failed test displayed with a
failed board,
but first check the “special cases” of diagnostic failures below:
H
If the “Calibration Checksums” repeatedly fails but Nonvolatile RAM
passes, replace the ACQ board.
H
If “Phase Lock Loop” and “VXI Time Correlation” fail, check the
backplane 10 MHz clock and, if needed, then replace the ACQ board.
H
Large numbers of acq failures could indicate an interconnect problem
between MPU and ACQ boards; check the interconnections
.
H
If you replace a board that is not calibrated, an uncalibrated error can
occur even though both boards are good. Calibration can fix the error.
Fault Isolation Procedure