iBook logic board
From Mac Guides
Over the last few years, Apple users have experienced persistent problems with the logic boards on some iBooks. Apple instituted extended logic board replacement past the normal warranty or AppleCare period for many of these iBooks.
The logic board of many iBook G3 computers failed over time, causing issues such as corrupted video, refusal to start up, and other problems. The iBook Logic board Repair program was started by Apple to address the problem of these defective boards at no cost to consumers, even when the warranty or AppleCare period had expired. Replacing the logic board usually fixed the problems — however, users have sometimes reported that the replacement logic board would ether cause additional problems or eventually fail in the same way.
Typically, if a specific iBook requires logic board replacement three times, Apple completely replaces that machine with an iBook G4 computer.