Setting The Minimum Contrast Level - Fluke 39 Service Manual

39/41B
Service Manual

4-19. Setting the Minimum Contrast Level

A minimum contrast level needs to be set whenever an LCD module, pca or the serial
EEPROM (U22) is replaced. This setting provides a minimum useful level so that a user
may not inadvertently set the screen blank.
1.
2.
3.
4.
5. Exit contrast mode normally.
6. Turn the Tester off and on.
The LCD contrast will be light but visible.
7. Return the Tester to optimum contrast.
4-18
C to put the Tester in contrast mode.
Press
< or > to set the display contrast to an optimum level (dark characters
Use
with light background).
C for at least 5 seconds. The contrast annunciator will turn off
Press and hold
during the first second, turn on for 3 seconds along with the backlight, and
then both will finally turn off. Release the contrast button.
Correct limit setting can be confirmed by changing the contrast to as light as
possible (by pressing C and holding
<).