Read an Excerpt
Chapter 1: Inside the iMac and PowerMacThis chapter is an introduction to the internal components of the desktop Macintosh computers that are covered by this book and how to gain access to them. Chapter 2 provides a similar introduction to the portable iBook and PowerBook models. Later chapters include specific information on each of the internal components and external peripherals used in or with these computers.
Just looking at the insides of a computer is intimidating for most people. There are a lot of enigmatic components in various shapes and sizes and a lot of wires and cables snaking all over the place without any obvious plan or design. However, the Macintosh computer is distinguished from all other computers by the comprehensive excellence of its design and engineering. You can be confident that every component inside the case of a Mac has been carefully designed to fit in with the functionality of the entire computer. The case design of all recent Macs provides access to components that are likely to require repair, replacement, or upgrading, while preventing you from damaging delicate components or accidentally injuring yourself.
Since this chapter involves a discussion of opening up computers and poking around inside, we should start with a few general points about safety and good habits when working on electronic equipment. You should also read Chapter 3 before beginning repairs and before you open the case of any Macintosh computer. If you plan to work with a specific component of the Mac, also familiarize yourself with that component using the appropriate chapters later in the book before you begin work.
There are a few important rules of thumb to keepin mind regarding maintaining and repairing computers:
First, never open the case of a computer (or any electrical device) while it is turned on.
Second, some computer components may heat up or store significant electric charges when the machine is operating, so allow the machine to cool off before beginning to work inside, and avoid touching any thing if you are not sure that it is safe.
Third, static electricity can damage electronic components. Always ground yourself before touching anything inside a computer. This can be done by touching a metal object, or better, by wearing a grounding or anti-static wrist strap that is attached to a metal part of the com puter case or to another ground (a grounding strap can be obtained for just a few dollars from any electronics store).
Finally, if it ain't broke, don't fix it. Even if it the computer is broken, randomly adjusting components that "don't look right" is not likely to lead to successful repairs. A systematic approach to repairs is required: remove and test parts that may be broken, or replace them with parts that are known to be okay.
What Desktop Macintosh Computers Are Covered in This Book?
This book contains information specific to only the Macintosh computers released after August of 1998. This includes all iMac models, the Blue and White Power Macintosh G3 (the earlier beige Power Mac G3 models originally released in 1997 are not covered), the Power Mac G4, and the Power Mac G4 Cube (which is covered separately in Chapter 42 because of its very recent release).
The Original iMac Models
The original iMac computers were released in August of 1998. They are the earliest computers covered by this book and were revolutionary Macs in many ways. They began Apple's shift away from earlier interface technologies like serial and SCSI ports, were the first USB Macs, and were the first Macs to feature the now-popular translucent look of virtually all of Apple's products. The iMac was also the first Mac in a long time aimed specifically at consumers and home users.
There were four revisions or changes in the original iMac's design over its 14-month life span. Revision A and B iMacs were available in only the original Bondi Blue color. They also included an infrared port and a special "mezzanine" expansion slot (which Apple discouraged developers from exploiting), which were removed from later revision iMacs. Revision C iMacs introduced the five fruit-flavored iMac colors and an increase in processor speed. Revision D iMacs only increased the iMac processor speed.
Table 1-1 shows the specifications for the original iMac...