User's Manual

123
Service Manual
4-4
Follow these general instructions for all tests:
• For all tests, power the test tool with the PM8907 power adapter. The battery pack
must be installed.
• Allow the 5500A to satisfy its specified warm-up period.
• For each test point , wait for the 5500A to settle.
• Allow the test tool a minimum of 20 minutes to warm up.
4.4 Display and Backlight Test
Proceed as follows to test the display and the backlight:
1. Press
TO TURN THE Test tool on.
2. Press
and verify that the backlight is dimmed. Then select maximum backlight
brightness again.
3. Remove the adapter power, and verify that the backlight is dimmed.
4. Apply the adapter power and verify that the backlight brightness is set to maximum.
5. Press and hold
.
6. Press and release .
7. Release
.
The test tool shows the calibration menu in the bottom of the display.
Do not press now! If you did, turn the test tool off and on, and start at 5.
8. Press (PREV) three times.
The test tool shows
Contrast (CL 0100):MANUAL
9. Press (CAL) .
The test tool shows a dark display; the test pattern as shown in Figure 4-1 may not be
visible or hardly visible.
Observe the display closely, and verify that no light pixels are shown.
Figure 4-1. Display Pixel Test Pattern
11. Press .
The test pattern is removed; the test tool shows
Contrast (CL 0110):MANUAL