Tektronix 684A User Manual

TDS 684A, TDS 744A, & TDS 784A Service Manual

This section contains the information needed to do periodic and corrective
maintenance on the TDS 684A and 7XXA Digitizing Oscilloscopes. The
following subsections are included:

H Preparation — Introduction plus general information on preventing damage

to internal modules when doing maintenance.

H Inspection and Cleaning — Information and procedures for inspecting the

oscilloscope and cleaning its external and internal modules.

H Removal/Replacement Instructions — Procedures for the removal of

defective modules and replacement of new or repaired modules. Also
included is a procedure for disassembly of the oscilloscope for cleaning.

H Troubleshooting — Information for isolating and troubleshooting failed

modules. Included are instructions for operating the oscilloscope’s internal
diagnostic routines and troubleshooting trees. Most of the trees make use of
these internal diagnostic routines to speed fault isolation to a module.

The following sections contain information/procedures related to maintenance.

H Section 2, Operating Information, covers instructions useful when operating

the oscilloscope in order to troubleshoot it. It also details the service strategy
and lists options for obtaining maintenance service and for replacing failed
modules.

H Section 3, Theory of Operation, contains a circuit description at the module,

or block, level.

H Section 4, Performance Verification, contains procedures that may be useful

in isolating problems to modules by testing oscilloscope performance.

H Section 5, Adjustment Procedures, addresses after repair adjustment and the

interval between periodic adjustments. It contains a procedure for adjusting
the internal circuits of the oscilloscope.

H Section 8, Replaceable Electrical Parts, lists all replaceable electrical parts

by part number.

H Section 9, Diagrams, contains a block diagram using individual modules as

blocks and an interconnection diagram showing connections between the
modules.