Apple ibook g4 12 inch mid 2005 User Manual

							
 
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iBook G4 (12-inch Mid 2005) Troubleshooting  Symptom Charts
10. If self-powered make sure that the power supply is connected and devices LED 
indicates that it is getting power.
11. Replace logic board. 
A USB device not recognized by computer
 
Note:  
 If you are trying to use a serial device with a USB/Serial adapter, check with the 
manufacturer of the adapter for compatibility.
1. Completely shut down, then press the power button to start the computer.
2. Try known-good Apple USB keyboard or mouse to verify the port is working properly.
3. Verify current driver for the device is installed.
4. If a camera, turn on camera after initiating download with camera application.
5. Try the other USB port.
6. Try known-good cable.
7. Try different USB device on same port.
8. Eliminate chain by plugging in only one peripheral.
9. Replace logic board. 
Sound
 
Distorted sound from speakers
 
1. Verify sound is correct with external speakers/headphones. If sound is correct, replace  top case.
2. Verify speaker cables are inserted correctly, and check cables for damage.
3. Check balance in System Preferences: Sound: Output.
4. Compare same sound with two different units to make sure that sound is actually  distorted.
5. Replace top case.
6. Replace logic board. 
No sound from speaker(s)
 
1. Reset PRAM (Press the power button, then hold down the Option-Command-P-R  keys until you hear the startup chime at least one additional time after the initial 
startup chime).
2. Verify that the speaker cable is connected properly to logic board, and check cable for  damage. 
						

							
 
iBook G4 (12-inch Mid 2005) Troubleshooting -   
9
 
 Symptom Charts 3. Use the Software Update control panel to verify that the latest audio update has been 
installed.
4. Press the F3 key (with the fn key pressed and not pressed) to verify that mute mode is  not enabled.
5. Press the F4 or F5 key (with the fn key pressed and not pressed) to check the volume  setting.
6. Verify no external speakers or headphones are plugged in.
7. Shutdown computer and restart.
8. Replace top case.
9. Replace logic board
Related articles: 75146: iBook Audio Update 1.3.6 Document and Software
58463: iBook: Sound Capabilities 
Startup
 
The computer will not power on
 
1. Remove any connected peripherals.
2. Try known-good power outlet.
3. Try known-good power adapter and power cord.
4. Remove battery.
5. Reset the power manager by pressing the key combination Control-Option-Shift- power.   
Warning: Make sure you do not hold down the fn key when resetting the 
power manager.
Warning: Resetting the power manager means you will also need to reset the 
date and time (using the Date & Time control panel).  
6. Reset PRAM (Press the power button, then hold down the Option-Command-P-R  keys until you hear the startup chime at least one additional time after the initial 
startup chime).
7. Disconnect internal keyboard completely. Inspect connectors. Restart with keyboard  disconnected. 
						

							
 
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iBook G4 (12-inch Mid 2005) Troubleshooting  Symptom Charts
8.
 
Important:  
 The AirPort Extreme/Bluetooth card has speci fic handling precautions. 
Make sure you review the section AirPort Extreme/Bluetooth Card in the Take Apart 
chapter before continuing.
Remove any additional RAM and AirPort Extreme/Bluetooth card.
9. Try known-good DC board.
10. Verify cable connections and check cables for damage.
11. Verify power button is connected properly to logic board, if power button is not  functioning correctly or damaged, replace the top case.
12. Replace logic board. 
At startup, a dialog box comes up stating “kernel panic” in Mac OS X 
 
1. If a RAM card is installed in the expansion slot, remove it and restart. • If symptom repeats, replace logic board.
• If symptom does not repeat, replace RAM card with known-good RAM card; r\
estart.
2. If no RAM card is installed, replace logic board.
Related article: 111772: iBook (Dual USB): Beeps Are Heard at Startup (one to four bee\
ps) 
Display
 
No display, or dim display, but computer appears to operate correctly (if dim, 
display shows startup icon and/or desktop)
 
1. Remove any connected peripherals.
2. Try known-good power outlet, power adapter and power cord.
3. Press F2 (with the fn key pressed and not pressed) to increase the screen brightness  setting.
4. Reboot the computer—hold down the Control and Command keys and press the  Power button, or press and hold the Power button for 5 to 10 seconds to shut down the 
computer, then press the Power button to restart.
5. Reset the power manager by pressing the key combination Control-Option-Shift- power.   
Warning: Make sure you do not hold down the fn key when resetting the 
power manager.
Warning: Resetting the power manager means you will also need to reset the 
date and time (using the Date & Time control panel). 
						

							
 
iBook G4 (12-inch Mid 2005) Troubleshooting -   
11
 
 Symptom Charts 6. Reset PRAM (Press the power button, then hold down the Option-Command-P-R 
keys until you hear the startup chime at least one additional time after the initial 
startup chime).
7. Connect an external display, and check for video on external display. • If video is fine on external display, troubleshoot LCD panel and verify \
cable connections to inverter and LCD.
• If video symptom is same on external display, replace logic board.
8. Verify backlight cable and LVDS cable connections are seated properly and that the  cables are not damaged (refer to display assembly replacement instructions).
9. Replace LCD panel.
10. Verify cable connections and check cables around the hinges for damage.
11. Replace logic board. 
When displaying a single color over the screen area, the LCD panel shows one 
or more pixels that are not properly lit
 
Active-matrix LCD technology uses rows and columns of addressable locations (pixels) 
that render text and images on screen. Each pixel location has three separate subpixels 
(red, green, and blue) that allow the image to be rendered in full color. Each subpixel has a 
corresponding transistor responsible for turning the subpixel on or off.
There are typically millions of these subpixels on an LCD display. For example, the LCD 
panel used in the Apple Cinema HD display is made up of 2.3 million pixels and 6.9 million 
red, green, and blue subpixels. Occasionally, a transistor does not work perfectly, which 
may result in the affected subpixel being turned on (bright) or turned off (dark). With the 
millions of subpixels on a display, it is quite possible to have a low number of faulty 
transistors on an LCD. Therefore, a certain number of subpixel anomalies is considered 
acceptable. Rejecting all but perfect LCD panels would signi ficantly increase the retail 
price for products using LCD displays. These factors apply to all manufacturers using LCD 
technology—not just Apple products.
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.
2. Using a jeweler’s loupe, pocket microscope, or other magnifying device, identify and  count each subpixel anomaly:
• Bright subpixel anomaly = subpixel that is always on
• Dark subpixel anomaly = subpixel that is always off 
						

							
 
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iBook G4 (12-inch Mid 2005) Troubleshooting  Symptom Charts
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 speci fications, and no repair is necessary.   
Important:  
  Do not release the specifications to customers. Instead, inform them t\
hat 
a certain number of subpixel anomalies is considered acceptable, and these factors 
apply to all manufacturers using LCD technology—not just Apple products. 
Scrambled or distorted video
 
Check for video on external display.
• If video is fine on external display, replace LVDS cable.
• If video is scrambled or distorted on external display, replace LCD pane\
l. 
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 Apples A/V Video Cable.
2. Make sure you are using the S-Video and Composite adapter cable.
3. In Mac OS X, go to the Displays system preference to change the 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 BrightDark  Combination
12.1 to 15.2 up to 3 up to 5 up to 7 4 or  more 6 or more 8 or more 
						

							
 
iBook G4 (12-inch Mid 2005) Troubleshooting -   
13
 
 Symptom Charts 
Display shows ghosting (signal re flection) 
 
1. Verify that cables are correctly installed and  firmly seated.
2. Replace video adapter. 
Video (VGA adapter)
 
No video on an external device
 
1. Verify monitor that is used in testing is known-good and is supported by this computer.
2. Try known-good VGA adapter.
3. Replace logic board.
4. Replace VGA adapter cable.
5. Replace logic board.  
Display shows ghosting (signal re flection) 
 
1. Verify that cables are correctly installed and  firmly seated.
2. Replace video adapter. 
Misc. Symptoms
 
The computer runs with battery, but not with the power adapter plugged into 
wall outlet
 
1. Try known-good power outlet. 
2. Try known-good power adapter and power cord. 
3. Reset the power manager by pressing the key combination Control-Option-Shift- power.   
Warning: Make sure you do not hold down the fn key when resetting the 
power manager.
Warning: Resetting the power manager means you will also need to reset the 
date and time (using the Date & Time control panel).  
4. Replace the DC-in board and verify connection to the logic board. 
5. Replace the logic board. 
Related article: 88133: iBook (Dual USB): Using PowerBook G4 Adapter 
						

							
 
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iBook G4 (12-inch Mid 2005) Troubleshooting  Symptom Charts 
The computer runs when plugged into a wall outlet but not on battery power
 
1. Reseat battery to verify battery is seated correctly with battery lock engaged.
2. Try known-good charged battery.
3. Reset the power manager by pressing the key combination Control-Option-Shift- power.   
Warning: Make sure you do not hold down the fn key when resetting the 
power manager.
Warning: Resetting the power manager means you will also need to reset the 
date and time (using the Date & Time control panel).  
4. Replace logic board. 
The cursor does not move when you are using trackpad
 
1. Verify that no USB device is connected.
2. Boot from a Mac OS system CD to verify that it is not a software problem.
3. Reset the power manager by pressing the key combination Control-Option-Shift- power.   
Warning: Make sure you do not hold down the fn key when resetting the 
power manager.
Warning: Resetting the power manager means you will also need to reset the 
date and time (using the Date & Time control panel).  
4. Check trackpad cable and connection to the logic board (see separate Top Case  replacement instructions for location under RAM shield).
5. Replace top case.
6. Replace logic board. 
The cursor intermittently does not move or moves erratically
 
Note:  
 User must touch with only one  finger at a time and point directly down on the 
trackpad surface.
1. Clean trackpad surface (with computer off, using a non-static-inducing material).
2. Reset the power manager by pressing the key combination Control-Option-Shift- power.   
Warning: Make sure you do not hold down the fn key when resetting the 
power manager.
Warning: Resetting the power manager means you will also need to reset the 
date and time (using the Date & Time control panel).  
3. Reset PRAM (Press the power button, then hold down the Option-Command-P-R  
						

							
 
iBook G4 (12-inch Mid 2005) Troubleshooting -   
15  
 Symptom Charts keys until you hear the startup chime at least one additional time after the initial 
startup chime).
4. Remove and reseat memory card.
5. Try unit on battery power. If problem goes away, replace power adapter.
6. Place a Mac OS system CD in the optical disc drive, press the start button and hold  down the “C” key. Check the cursor movement, to see if the problem is software.
7. Check trackpad cable and connection to the logic board (see separate Top Case  replacement instructions for location under RAM shield).
8. Replace top case.
9. Reseat the heatsink if it is not properly secured.
10. Replace logic board. 
The microphone is not working
 
1. Check the signal level and level meter and adjust the gain.
2. Reset PRAM (Press the power button, then hold down the Option-Command-P-R  keys until you hear the startup chime at least one additional time after the initial 
startup chime).
3. Verify microphone cable connection to logic board, and check cable for damage.
4. Replace microphone cable.
5. Replace logic board. 
The latching mechanism that holds the display closed is not working
 
Note:   
As the display closes against the top case, a hook in the top of the display housing 
should be magnetically pulled down into a slot in the top case, and secured. When the 
latch button is pushed, the hook should release and retract into the display housing, 
allowing the display to open.
1. Verify hook operation by exercising the latch mechanism. 
2. If the hook does not operate properly, replace the display bezel.
3. If the latch or latch button does not operate properly, replace the top case assembly. 
Fan fails
 
1. Check fan cable connection, and check cable for damage.
2. Check fan for loose parts stuck in fan blades.
3. Replace fan.
4. Replace logic board. 
						

							
 
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iBook G4 (12-inch Mid 2005) Troubleshooting  Symptom Charts 
Trackpad works intermittently
 
The trackpad operation can be affected by hand lotion, humidity, dangling jewelry, and the 
use of more than one  finger on the trackpad. 
1. Check for environmental factors such as humidity, hand lotion, or jewelry.
2. Clean the trackpad with a clean, dry lint-free cloth. 
Related articles: 17228: Portables: Jumpy or Erratic Trackpad Operation
58389: PowerBook and iBook: Trackpad Does Not Respond
Greasy substance in battery bay
A small amount of grease is used on the springs in the battery bay. Inform customers that 
the grease helps the springs operate correctly. The grease is not harmful and should not 
cause alarm. However, if it comes in contact with skin, wash it off with soap and water.
Refer to Knowledge Base article 88369: iBook: White Greasy Substance in Battery Bay. 
						

							
iBook G4 (12-inch Mid 2005) Troubleshooting - 17
 Symptom Charts
Block Diagram
External
display
connector
Ethernet port FireWire port
Internal
speakers Headphone port
Internal
microphone
AGP 4X
bus
Memory bus 133 or
142 MHz MaxBus
PMU99
power controller
Trackpad
Keyboard
Power supply and charger
SO-DIMM connector
Graphics IC
32 MB DRAM
Flat-panel display
Audio
system
Ethernet PHY
FireWirePHY
PowerPC G4
microprocessor
(L2 cache: 512 KB)
512 MB on-board SDRAM
PCI bus
Boot
ROM
USB 2.0 port
USB 2.0 port
PCI USB
controller
AirPort
Extreme
ATA-100 bus
EIDE bus
Connector to internal
IDE disk drive
Connector to internal
optical drive
I
2S
USB 1.1Modem port
Modem moduleBluetooth
Data pump and DAA
Intrepid
memory
controller and I/Odevice
controller