Performance Tests
TDS 684A, TDS 744A, & TDS 784A Service Manual 4–27
Signal Acquisition System Checks
These procedures check those characteristics that relate to the signal-acquisition
system and are listed as checked under Warranted Characteristics in Specifica-
tions.
Equipment
Required None
Prerequisites The oscilloscope must meet the prerequisites listed on page 4–15
1. Preset the instrument controls:
a. Initialize the oscilloscope:
HPress save/recall SETUP.
HPress the main-menu button Recall Factory Setup.
HPress the side-menu button OK Confirm Factory Init.
HPress CLEAR MENU to remove the menus from the screen.
b. Modify the default settings:
HPress SHIFT; then press ACQUIRE MENU.
HOn the TDS 684A, press the main-menu button Mode; then press
the side-menu button Average 16.
HOn the TDS 7XXA, press the main-menu button Mode; then press
the side-menu button Hi Res.
HPress CURSOR.
HPress the main-menu button Function; then press the side-menu
button H Bars.
HPress CLEAR MENU.
HBe sure to disconnect any input signals from all four channels.
2. Confirm input channels are within limits for offset accuracy at zero offset:
Do the following substeps — test CH 1 first, skipping substep a since CH 1
is already set up to be checked from step 1.
a. Select an unchecked channel: Press WAVEFORM OFF to remove the
channel just confirmed from the display. Then, press the front-panel
button that corresponds to the channel you are to confirm.

Check Offset Accuracy

(Zero Setting)