Keithley SourceMeter 2400, Service Manual, Page: 57 / 137

4-3 Model 2400 Service Manual
Troubleshooting
2400-902-01 (G - Feb 2006)
Front panel tests
There are three front panel tests: one to test the functionality of the front panel keys and two to
test the display. In the event of a test failure, refer to Display board checks for details on trou-
bleshooting the display board.
KEYS test
The KEYS test allows you to check the functionality of each front panel key. Perform the fol-
lowing steps to run the KEYS 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 KEYS, and press ENTER to start the test. When a key is pressed, the label name
for that key will be displayed to indicate that it is functioning properly. When the key is
released, the “No keys pressed” message is displayed.
5. Pressing EXIT tests the EXIT key. However, the second consecutive press of EXIT
aborts the test and returns the instrument to the SELF-TEST MENU. Continue pressing
EXIT to back out of the menu structure.
DISPLAY PATTERNS test
The display test allows you to 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:
• Checkerboard pattern (alternate pixels on) and all annunciators.
• Checkerboard pattern and the annunciators that are on during normal operation.
• 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
SELF-TEST MENU. Continue pressing EXIT to back out of the menu structure.