Brief Procedures; Self Tests - Tektronix TDS 420A Service Manual

Brief Procedures

Self Tests

Verify Internal Adjustment,
Self Compensation, and
Diagnostics
TDS 420A, TDS 430A & TDS 460A Service Manual
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 use the probe-adjust output at the front panel as a test-
signal source for further verifying that the oscilloscope functions properly. A
standard-accessory probe, included with this oscilloscope, is the only
equipment required.
This procedure uses internal routines to verify that this oscilloscope functions
and passes its internal self tests and signal path compensations. It also confirms
that the oscilloscope was adjusted properly at the time it was last adjusted. No
test equipment or hookups are required.
Equipment None
Required
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 that
the internal diagnostics passed.
a. Display the system diagnostics menu:
H Press SHIFT; then press UTILITY.
H Repeatedly press the main-menu button System until Diag/Err is
highlighted in the menu that pops up.
H Repeatedly press the main-menu button Area until All is highlighted
in the menu that pops up.
b. Run the system diagnostics: Press 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 takes up to two minutes. While it
progresses, a variety of test patterns flash on screen. When finished, the
resulting status appears on the screen.
d. Confirm no failures are found: Verify that no failures are found and
reported on screen.
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