Blank blue screen always appears after Apple icon
Hi! I often get iBook G4s that can go into the option menu and target mode, but when you select a volume to boot from, or let them boot to the hard drive, they go to a blank light blue screen and then stall. This happens immediately after the Apple icon screen. The Apple icon screen will disappear after a while, there will be a sort of a flash of a screen refresh, and then the laptop will sit on a blank blue screen, and that's it. I've tried all the typical stuff -- removed the RAM and Airport, done PRAM/PMU resets, swapped the hard drive, tried booting to an external drive, etc. It doesn't matter if you try to boot to the internal drive, external drive, or restore media.
I can only assume it's a logic board issue, because I've tried everything I can think of. There are a lot of machines like this, and it's frustrating to let them go, because they seem like they are close to working, and it feels like I'm missing something.
Strip the iBook to the logic board level (now you get only the logic board), connect a known working DC in board, connect an external monitor, connect the AC adapter and power the logic board by tripping the two pins in the power switch connector. Check if you get the fashing question mark. If so connect an external firewire hard drive with compatible OS on it, try to boot tripping the two pins. If you still have the same blue screen issue then the logic board is bad.
Could you try one thing before going after the hardware. Restart the computer and hold down the Shift key until the blue screen comes up and then for about 30 seconds more. I have seen on other machines that when there have been a disturbance with the system, going into safe mode sometimes lets the system recover and then the restart after that it comes up.
It won't hurt to try and see if by chance it helps.
There a lot of little issue like that related to the failure of what I understand to be a power control chip that controls power to the video processing chip..
I was able to fix on like this with a big wad of electrical tape jammed between the chip and the emi shield.
some people call it a c-clamp fix..
Here's some more info.. http://www.xlr8yourmac.com/tips/iBookG4_...
I've got the same "blue screen" issue with an 800 MHz iBook G4. This is definitely some sort of logic board issue, as I can temporarily get the iBook to boot normally by squeezing the case to the left of the trackpad. However, once it does boot, it typically locks up within a few minutes (i.e. cursor freezes, display does not change) and you have to hold down the power button to force it to turn off.
Based on what I've read on the web, this problem can be due to bad solder connections on a voltage regulator chip, or defective solder balls on the ATI video chip. In my case, I resoldered the pins on the voltage regulator, but the problem persists.
There are companies that can fix the video chip issue, but you've got to tear your iBook down to the bare logic board and ship it to them for repair.