Computer has Bootup problems.

Okay, so it's not even loading the disk?

Which exact version of the iBook is it?

Do you know the processor speed?

There are a few tings to try here, but I'd need to know the model.

What I would do at this point with your iBook is try unplugging the Airport Card. (Removal)

Then retry the AHT and see if you get that INVALID MEMORY ACCESS

Here is how to access the Airport Card.

http://www.ifixit.com/Guide/Installing+iBook+G4+14-Inch+1.42+GHz+AirPort+Extreme +Card/737/1

Just take your time.

Don't worry about screwing the case back together when trying to retry the AHT.

Just clip the outer casing in place, as you will need to access in inside again and saves you unscrewing all the case screws again.

Let us know how it performs.

I've done this a few times while working for Apple and I know the 14" 1.4Ghz model is not one of the easiest to get into. (Not the hardest, the first iBook was harder) Just make sure any unplugged connectors are reconnected on assembly.

Best of luck

Hello,

Could you try somthing for me and let me know what the outcome is.

Place the iBook on a flat surface like a table/desk

Make sure it's plugged in. With your palm, place it next to the left side tracker pad and apply pressure.

While doing so, switch the iBook on with your free hand.

Keep applying pressure until it boots. (You may need to press hard, do worry, it would take a look of force to break it) Let us know what happens.

Hello,

Indeed holding it down may help it to keep running.

Let me explain what I believe the problem is.

The iBook G4 14" 1.4Ghz suffered like many iBooks with a problem to their logic board.

The problem in question relates to two main chip soldered to the logic board. Due to poor solder or cooling problems, the chip would get hot and cool over time. With inadequate solder, in time one or two chip legs would become unsoldered to the board when they get hot. One chip controls the IDE to the hard drive.

At first it may appear to be a fault with the hard drive. A replacement drive won't help.

When you push down on the case, you effectively pushing the problem chip to the logic board, therefore making good contact. The problem can be easily resolved by chip removal and resolder, however not everyone has such equipment to do this. I've fixed many that have suffered this problem before, including the renowned fault with the GPU (Graphics Processor Unit) on the iBook G3 models.

There are only two fixes, a replacement logic board or reslodering the chips on the logic board by a specialist.

If you web search Ibook GPU problem, you will find many web posts regarding this problem.

It's key to diagnose the problems before spending money on parts that may not be required.

The bet way to diagnose this chip problem is like you ave done, applying pressure to the left side of the tracker pad and see if all works fine.