While I was on the internet my ibook g4 locked up. I tried to restart but it continued to lock up. I tried to reinstall OS10 but the computer locked up in the middle of the install. I have replaced the memory card and hard drive with the same results. What else could be wrong? Logic board? I am lost here.

if you or a friend have another Mac, use it to start up the iBook in Firewire mode (hold the T key on the laptop when restarting). You can reinstall the operating system, or try to simply repair the disk with Disk Utility.

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that's a kernel panic, which means there's probably a problem with your operating system. Use the original disks to reinstall the OS.

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Try SMC and PRAM reset. To do this you need to google the model number and the reset instructions. If that does not work you need to reinstall the OSX

Dude, if you have all the current updates for your OS and applications, then you got a logic board issue. Especially if you you keep seeing the spinning beach ball of death or the dreaded white screen of death. 
The iBook G4 is the poster child for logic board defects, because it has to do with the way the circuit boards were flowed.  Apple won't fix this for the iBook G4.  You got to do a big class action lawsuit like they did with the iBook G3 before they will replace the logic board.
Best bet is to sell this thing on e-bay as a non-working unit and get you a better laptop.

Leopard is not really suited for the iBook G4.  I would recommend you go back to Tiger and see if that gets rid of your lockup.  Leopard is more suitable for the Macbook.

Identifying lock-ups and freezes Close locked-up programs and locate problem software Uninstall and re-install the problem software Contact the software vendor Understanding backwards compatibility issues Change the operating system emulation with the Program Compatibility Wizard This document pertains to HP Notebook PCs with Windows Vista. Identifying lock-ups and freezes This document will help you to locate and troubleshoot programs that cause your notebook to hang, freeze, or lock-up. Print this document or save it to your hard disk drive to have the reference available after disconnecting from the internet. Symptoms of notebook lock-ups, freezes, and hangs include:

• Nothing moves or blinks on the computer display.
• The computer will not respond to the mouse or keyboard.
• An error message appears and will not go away.

Freezes, crashes, and lock-ups may be caused by programs locking up resources, software conflicts, or older programs being incompatible with newer operating systems. Follow the steps in this document, in order, until the problem is resolved. Close locked-up programs and locate problem software If your notebook locks up or stops responding while using a program, close the stalled program to continue using other programs. Also, while closing the program, take note of which other programs are running at the same time.

1. Close the program that is "Not responding" and determine if the lock-ups continue.
2. If the lock-ups no longer occur after the program is closed, go to Uninstall and re-install the problem software .
3. If the lockups continue, press ctrl + alt + delete to go back to the Task Manager.
4. Write down all of the programs that are running when the lock-up occurs. The conflict could have originated by another software application that is running at the same time.
5. Close other programs that are running one at a time (except for Explorer and Systray) and determine if the lockups continue. Once you find the problematic software application, go to Uninstall and re-install the problem software .

Uninstall and re-install the problem software To resolve the problem that is causing the notebook to lock-up, uninstall the suspected software and then re-install it. If your software came with an uninstaller program, use it first; otherwise, follow the steps below to uninstall and re-install the program.

1. Click Start > Control Panel .
2. When the Control Panel window opens, select Uninstall a program.
3. Select the program that is causing the lockups and right-click it. Then select Uninstall . NOTE: Remove all versions of the same program. Sometimes upgrades will not remove old versions of the software before installing the new version. This leaves multiple versions of the same software on your computer.
4. After removing the problem programs, close the Control Panel.
5. Restart the computer.
6. Re-install the program following the vendor's instructions

Try resetting the PRAM by turning on the iBook then holding option + command + P + R and wait till u hear another chime. If it still freezes, it may indicate an application may be causing it to lock up hold shift after you hear the chime to boot OS X into safe boot.

Hold down the Apple and the E when you restart your computer.

reinstall your system.  what system are you using?

You can go to the Apple (top left) and on the drop down menu, select "force quit"(which is similar to CTRL-ALT-delete on PC) and quit the program that is locking up.The fact that it locks up with 4 screns oprned tells me that the iBook may need more memory.I believe that the iBooks come with 256 MB. You can add memory and keep this from happening.
If I could be of further assistance, let me know. If this helps or solves the issue, please rate it.
Thanks, Joe



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