iBook screen problems: Injured wires, logic board failure

There is an issue with several iBook units involving failing displays that we first reported on in-depth in mid-March and April of this year. Since those initial postings, Apple's discussion boards and MacFixIt's forums have been inundated with similar reports, leading to the notion that there may be a serious design flaw in Apple's dual-USB iBooks.

The problem most users are experiencing is a design flaw at the hinge to the display. Apparently there isn't enough room for the wires to pass through and handle the friction they receive by opening and closing the lid.

To recap, the problem generally manifests in one of three ways:

• Video "artifacts" progressing to eventual system failure
• "Black screen" or "dimming" of the backlight, when screen is opened past a certain angle
• "Black screen" or "dimming" of the backlight at random times, which can be temporarily solved by tapping on, or applying pressure to, the iBook case directly below the fn and control keys (to the left of the trackpad)

MacFixIt reader Peter H did an excellent take-apart analysis of the problem, yielding the following findings:

"You are absolutely correct about the display hinges. The edges are sharp and they cramp the wires. As the display is opened and closed the wires are forced to bend and twist repeatedly about too small a radius. As the lid is opened they are also put into tension. The wires, such as the backlight cable, are only 7 strand and will not tolerate this repeated physical stress and will fail from fatigue / strain hardening.

"You are also correct about shorting to earth. My daughter's iBook leaks high voltage through the exposed metal fasteners on the underside and she can't use it on her bare legs without getting a moderate but still intolerable electric shock. (This showed up within a few months of being purchased. Initially I thought she was joking but I have verified it and it is true. )

"I repaired the broken backlight (black wire on RHS) by splicing in a new segment of more appropriate cable able to withstand repeated flexing. I also opened out the semi circular space where the wires pass through the hinge and smoothed out the sharp edges. This is a mechanical design flaw and the wrong type of cable is being used in this demanding area. Given the small dimensions inside the hinge it is difficult to resolve as a service issue.

"Generally the (short term) solution to the problem I experienced is to replace the backlight cable, but Apple technicians are repeatedly replacing the whole display (I believe this is an error in Apple's workshop manual - which I have read BTW)

"I also did a thorough examination of the motherboard with a stereo inspection microscope and I see a problem with high voltage arcing across to the RF shield. The characteristic pitting was quite obvious under the microscope. (no wonder you may be exposed to an electric shock from the bare metal on the underside of the iBook). I imagine the shorting would also not help battery life. Also I noted that many of the cables are RF shielded with a finely woven metallic sheath. This is OK but I observed at the cut ends - stray fine metallic fibers which in some cases were making inappropriate contact potentially shorting out some electronic components. In my opinion, some areas of the design and fabrication are superb. Other areas leave much to be desired."

"It seems Apple really needs to improve Quality Control and more stringent review of design issues. If I put out a product with these flaws I would expect to lose Quality Assurance Certification."

As we suggested back in March, purchasing an AppleCare extended warranty plan - or avoiding current model revisions altogether - seem to be the best bets for prospective new iBook buyers. Out-of-pocket iBook logic board replacements can be quite expensive. Readers have been quoted prices ranging from US$400 to US$920 for screen replacement and/or logic board repair.

One reader writes "They (Apple) told me it was the logic board and that the repair would be $920. I opted to buy a new iBook/800 G4 from another source. This time I got the AppleCare program."

Feedback? Late-breakers@macfixit.com.

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