strange ibook display problem

[gonyr]

also posted on apple discussion forums...

My wife has a 12" ibook g4 1.33 mhz. It has been exhibiting the following symptoms with increasing frequency:

1) the display will completely dim to the lowest setting or cycle between bright and dim, as if pressing f1 and/or f2 repeatedly
2) some of whatever she was typing or working on at the time will be deleted
3) a string of repeated characters (usually q1aq1aq1a) will appear in her typing
4) often the desktop is brought to the front as if pressing f11 in expose
5) other than the problems described, the computer continues to work normally
6) problems are almost always related to moving the hinge position, but sometimes happen randomly, with no movement at all
7) it will sometimes occur many times a day, then not at all for several days
8) it seems to happen more often when the computer is not on a hard surface, but this may just be my imagination or some random bad luck

I am at a loss as to what the problem may be. I was thinking it might be the display cable because of the link to hinge position, but that wouldn't account for the random typing. Then I thought it was the motherboard, but the computer seems to work ok other than this. I did realize the other day that most of the problems are things on the left hand edge of the keyboard (display brightness, the q1a pattern), but this doesn't account for the deleted typing and the mysterious f11 thing.

Does anybody have any thoughts? Am I looking at a display cable (hopefully this is it - I have no problems with disassembling/reassembling things)? Or is it the motherboard (probably means it would be more economical to get a new machine)? Or is it something else?

Thanks for taking the time to read all this, and I appreciate any help you can provide.

 

[Machyper]

Have you been using the keyboards too much, also how long have you bought it? Electronics always have an ending. If it is a serious problem, go buy a new Macbook. It is worth to start fresh if it will disturb your wife.

 

[gonyr]

I'm not quite sure what you mean by "use the keyboards too much". It's not like anyone has been writing a novel or anything.

Suggesting the purchase of a new computer just because electronics have a lifespan isn't really helpful. This ibook is only three years old, well within it's expected life. If you have a reason why you think it needs to be replaced, let me know, but I get the feeling you're suggesting replacement just because it's not the latest model. Do you buy a new car when yours breaks down?

 

[techound1]

You can pick a replacement keyboard on ebay relatively cheaply and it's one of the easiest parts to replace on an iBook.

Up until you described the problem with the hinges/opening, I was sure it was simply a shorting keyboard. Because it also seems to be triggered by moving or flexing the ibook, it may simply be that the keyboard connection to the logic board has gotten a bit loose. Visit ifixit.com to see how to pop the keyboard off, reseat the keyboard-logic board connection and see how that does. If it doesn't resolve it, go for the replacement keyboard. If you still have an issue, my next stop would be to check for a floating piece of metal that is shorting things on the logic board (happens with amazing frequency in iBooks as the tabs break off of the metal shields).

 

[gonyr]

Based on suggestions here and on apple discussion forums, I switched the keyboard with the one from my other ibook (the only other keyboard I had available). So far, both machines are functioning normally. The keyboard connection may have come loose when I installed ram a while back. I never disconnected it, just flipped it over to access the ram slot. Unfortunately, with both ibooks working at the moment, I can't tell yet if the problem has been solved, or if it's just one of those lucky days where the malfunctions don't pop up.

My assumptions are that if the problem follows the keyboard to the other machine = bad keyboard, easy fix. If the problems stop = bad keyboard connection, already fixed. If the problems stay on the original ibook = bad news, as I'm pretty sure there's no loose metal in there.

 

[techound1]

Agreed with one exception (assuming the problem creeps back up). Before you chuck in the sponge on the whole computer (and end up getting much less for it on resale), take out the logic board and have a peek. You may be very surprised.

 

[gonyr]

Well, it's been a week, and both machines are working well with some pretty heavy usage. I guess it was just a loose keyboard cable after all. Macrumors forums solves another one - you guys are great.

Thanks, techound1