Q&A STEVE ALEXANDER
Q I have a three-year-old Apple iMac G5 desktop computer. In August, the screen started displaying a series of small, randomly distributed vertical lines. By late September, the number of lines had increased to 33.
Apple told me that the screen can't be fixed and that a new one will cost $500. But they can't tell me why this is happening, and I hesitate to buy a new screen without knowing the reason for the problem. What should I do?
DAVID VAN GIESON, MINNEAPOLIS
A It's not clear that the screen needs to be replaced. You need a technician to check out three potential problem areas.
It's possible the problem is caused by a loose connection between the screen and main circuit board, which could be fixed easily. Or the problem could be that there's a flaw in the computer's video chip -- which could be replaced. Or the LCD screen could have malfunctioned because of an internal electrical failure and need replacement.
For the benefit of other readers: Because the iMac G5 has the computer and the screen bundled into a single rectangular unit (it was supposed to resemble an early iPod), replacing the screen isn't a matter of going to the computer store and picking one out. A replacement part from Apple is required.
If the screen has to be replaced, the Apple technician's estimate of $500 for purchase and installation was pretty close. For another repair shop's prices, see www.dttservice.com/imac/imacg5.html.
Why would your LCD screen fail? Inside the display, a flexible circuit board delivers signals to the screen. If the screen and the circuit board become partly separated -- perhaps because the computer was jolted or exposed to extreme temperatures (such as leaving it in a car in the winter) -- horizontal or vertical lines appear on the screen because those areas aren't receiving an electrical signal.
