Apple g4 Laptop User Manual


 
PowerBook G4 (1GHz/867MHz) Troubleshooting - 8
Battery Symptom Charts
Display
Display latch not working
Note: When the display is being closed, a latch hook in the top of the display housing
should be magnetically pulled down through the slot in the top case and secured by the
latch mechanism. When the latch button is pushed, the hook should release and retract
into the display housing.
1. See the Latch Adjustment chapter in the Adjustments section of this service manual to
verify the latch mechanism and latch hook operation and make adjustments, if
necessary.
2. If the latch hook is broken, replace the display panel assembly.
When displaying a single color over the screen area, the LCD panel shows one
or more pixels that are not properly lit
To determine whether or not the display has an acceptable number of pixel anomalies,
follow the steps below:
1. Set the display image to one of the following colors: all-white display, all-red display,
all-green display, or all-blue display. Knowledge Base article 112125: Service
Diagnostics Matrix, has the LCD Tester Diagnostic Utility that will generate these
patterns on the screen.
2. Using a jeweler’s loupe, pocket microscope, or other magnifying device, identify and
count each pixel anomaly:
Bright subpixel anomaly = subpixel that is always on
Dark subpixel anomaly = subpixel that is always off
3. The number of acceptable pixel anomalies for this system is:
Acceptable Number of Subpixel Anomalies
4. If the number of subpixel anomalies exceeds the acceptable number listed in the
above chart, replace the display panel assembly.
Replace
Bright Up to 3
Dark Up to 5
Combination Up to 7
Bright 4 or more
Dark 6 or more
Combination 8 or more