Keithley SourceMeter 2425, Service Manual, Page: 69 / 141

4-4 Troubleshooting Model 2425 Service Manual
DISPLAY PATTERNS test
The display test lets you verify that each pixel and annunciator in the vacuum fluorescent
display is working properly. Perform the following steps to run the display test:
1. Display the MAIN MENU by pressing the MENU key.
2. Select TEST, and press ENTER to display the SELF-TEST MENU.
3. Select DISPLAY-TESTS, and press ENTER to display the following menu:
FRONT PANEL TESTS
KEYS DISPLAY-PATTERNS CHAR-SET
4. Select DISPLAY-PATTERNS, and press ENTER to start the display test. There
are five parts to the display test. Each time a front panel key (except EXIT) is
pressed, the next part of the test sequence is selected. The five parts of the test
sequence are as follows:
• Checkerboard pattern (alternate pixels on) and all annunciators.
• Checkerboard pattern and the annunciators that are on during normal opera-
tion.
• Horizontal lines (pixels) of the first digit are sequenced.
• Vertical lines (pixels) of the first digit are sequenced.
• Each digit (and adjacent annunciator) is sequenced. All the pixels of the
selected digit are on.
5. When finished, abort the display test by pressing EXIT. The instrument returns to
the FRONT PANEL TESTS MENU. Continue pressing EXIT to back out of the
menu structure.
CHAR SET test
The character set test lets you display all characters. Perform the following steps to run the
character set test:
1. Display the MAIN MENU by pressing the MENU key.
2. Select TEST, and press ENTER to display the SELF-TEST MENU.
3. Select DISPLAY-TESTS, and press ENTER to display the following menu:
FRONT PANEL TESTS
KEYS DISPLAY-PATTERNS CHAR-SET
4. Select CHAR-SET, and press ENTER to start the character set test. Press any key
except EXIT to cycle through all displayable characters.
5. When finished, abort the character set test by pressing EXIT. The instrument
returns to the FRONT PANEL TESTS MENU. Continue pressing EXIT to back
out of the menu structure.