Tektronix 744A User Manual

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

This subsection contains information and procedures designed to help you isolate
faulty modules in the oscilloscope. If a module needs to be replaced, follow the
Removal and Installation Procedures located in this section.

The oscilloscope has two levels of internal diagnostics that focus on verifying,
adjusting, and if need be, isolating faulty modules.

Both levels of internal diagnostics report any bad modules and/or interfaces. If a
bad module and/or interface is found, use the troubleshooting procedures in this
section to determine which module needs to be replaced.

The two levels of diagnostics are the short confidence set and the extended set
that tests the oscilloscope circuitry in depth and takes more time. At power-on,
the oscilloscope automatically executes the short set. The extended set is
optional and is executed by using the following procedure:

Prerequisites: Power on the oscilloscope and allow a 20 minute warm-up before
doing this procedure.

1. Display the System diagnostics menu:

a. Press SHIFT; then press UTILITY.

b. Repeatedly press the main-menu button System until Diag/Err is

highlighted in the pop-up menu.

2. Run the System Diagnostics: Press the main-menu button Execute; then

press the side-menu button OK Confirm Run Test.

3. Wait: The internal diagnostics do an exhaustive verification of proper

oscilloscope function. This verification will take about two minutes. When
finished, the oscilloscope will display a report of any bad modules and/or
interfaces.