User Guide

10 - PowerBook G4 (12-inch) Troubleshooting
Symptom Charts
count each subpixel anomaly:
• Bright subpixel anomaly = subpixel that is always on
• Dark subpixel anomaly = subpixel that is always off
3.
Important: Check the number of subpixel anomalies with the following chart:
4. If the number of subpixel anomalies exceeds the acceptable number listed in the
chart, replace the LCD panel.
5. If the number of subpixel anomalies is acceptable, explain to the customer that the
pixel anomalies are within specifications, and no repair is necessary.
Important: Do not release the specifications to customers. Instead, inform them that
a certain number of subpixel anomalies is considered acceptable, and these factors
apply to all manufacturers using LCD technology—not just Apple products.
Video (S-Video and Composite adapter)
No video on an external device
1. Make sure you are using the S-Video and Composite adapter cable.
2. Verify TV or VCR is set up properly with correct source.
3. Try different TV or VCR. Check owner’s manual for TV or VCR.
4. Replace adapter cable.
5. Replace logic board.
The display is rolling (PAL instead of NTSC)
1. Make sure you are not using Apple's A/V Video Cable.
2. Make sure you are using the S-Video and Composite adapter cable.
3. Go to Displays preference pane; change resolution from PAL setting to NTSC setting.
4. Try a different TV or VCR.
5. Try a different adapter cable
6. Replace logic board.
LCD Size
(inches)
Acceptable Number of Subpixel
Anomalies
Replace the LCD Panel
Bright Dark Combination Bright Dark Combination
12.1 to 15.2 up to 3 up to 5 up to 7 4 or more 6 or more 8 or more