TDS 684A, TDS 744A, & TDS 784A Service Manual 4–5
Brief Procedures
The Self Tests use internal routines to confirm basic functionality and proper
adjustment. No test equipment is required to do these test procedures.
The Functional Tests utilize the probe-compensation output at the front panel as
a test-signal source for further verifying that the oscilloscope functions properly.
A probe, such as the P6245, is required to do these test procedures.

Self Tests

This procedure uses internal routines to verify that the oscilloscope functions and
was adjusted properly. No test equipment or hookups are required.
Equipment
Required None
Prerequisites Power on the Digitizing Oscilloscope and allow a 20 minute warm-up
before doing this procedure.
1. Verify that internal diagnostics pass: Do the following substeps to verify
passing of internal diagnostics.
a. Display the System diagnostics menu:
HPress SHIFT; then press UTILITY.
HRepeatedly press the main-menu button System until Diag/Err is
highlighted in the pop-up menu.
b. Run the System Diagnostics:
HFirst disconnect any input signals from all four channels.
HPress the main-menu button Execute; then press the side-menu
button OK Confirm Run Test.
c. Wait: The internal diagnostics do an exhaustive verification of proper
oscilloscope function. This verification will take up to three and a half
minutes on some models. At some time during the wait, a “clock” icon
(shown at left) will appear on-screen. When the verification is finished,
the resulting status will appear on the screen.
d. Confirm no failures are found: Verify that no failures are found and
reported on-screen.

Verify Internal Adjustment,

Self Compensation, and

Diagnostics