3411-B Scaler Module Test Functions
The 3411-B microprocessor controls the majority of the
instrument’s functions. If the display indicates four zeros (0000)
when the instrument is turned on, the microprocessor is
probably working normally.
If the microprocessor is working, there are three self-test
routines that can be used to verify proper operation. To enter
the routines, depress the
〈SHIFT〉 key and the 〈TST〉 keys at the
same time. Each repeated depression of the
〈SHIFT〉 and 〈TST〉
keys indexes to the next test.
To return the instrument to the normal mode, hold the 〈SHIFT〉
key down while pressing and releasing the
〈STANDARD〉 key.
Release the
〈SHIFT〉 key and the instrument will also return to
the normal mode of operation if it is turned off and on again.
SELF-TEST 1: 3411-B DISPLAY TEST
This routine produces a cyclic number sequence that ripples
across the display. The exact sequence is shown in the figure
below. By watching each digit “count up,” you can verify that the
LCD and its associated electronics are working properly.
Figure 10. 3411-B Display Test Sequence