Brief Procedures
TDS 684A, TDS 744A, & TDS 784A Service Manual 4–9
2. Verify that all channels operate: Do the following substeps — test CH 1
first, skipping substep a and b since CH 1 is already set up for verification
and as the trigger source from step 1.
a. Select an unverified channel:
HPress WAVEFORM OFF to remove the channel just verified from
display.
HPress the front-panel button that corresponds to the channel you are
to verify.
HMove the probe to the channel you selected.
b. Match the trigger source to the channel selected:
HPress TRIGGER MENU.
HPress the main-menu button Source.
HPress the side-menu button that corresponds to the channel selected
(Ch2, Ch3, or Ch4).
c. Set up the selected channel:
HSet the vertical SCALE to 200 mV.
HSet the horizontal SCALE to 200 ms. Press CLEAR MENU to
remove any menu that may be on the screen.
d. Verify that the channel is operational: Confirm that the following
statements are true.
HThe vertical scale readout for the channel under test shows a setting
of 200 mV, and a square-wave probe-compensation signal about
2.5 divisions in amplitude is on-screen. See Figure 4–1 on page 4–3
to locate the readout.
HThe vertical POSITION knob moves the signal up and down the
screen when rotated.
HTurning the vertical SCALE knob counterclockwise decreases the
amplitude of the waveform on-screen, turning the knob clockwise
increases the amplitude, and returning the knob to 200 mV returns
the amplitude to about 2.5 divisions.
e. Verify that the channel acquires in all acquisition modes: Press SHIFT;
then press ACQUIRE MENU. Use the side menu to select, in turn, each
of the three hardware acquire modes and confirm that the following
statements are true. Refer to the icons at the left of each statement as you
confirm those statements.