Apple 8200 appendix Repairing a damaged disk, When do you need to repair a disk?

Repairing a damaged disk

Disks can become damaged by repeated use and handling.

When do you need to repair a disk?

If you see a message reporting that a disk is damaged or unreadable, you may need to repair the disk.

Try these suggestions first

If you can’t start up from a hard disk or you don’t see the hard disk icon on the desktop, try the following:

mIf the hard disk is internal, shut down your Macintosh, wait at least 10 seconds, and then turn it on again.

mIf the hard disk is external, make sure that it is turned on and that its cable is connected firmly; then restart the Macintosh.

mIf the hard disk is your startup disk, start up with a different startup disk. If the hard disk’s icon appears on your desktop, reinstall system software on the hard disk. See “Installing or Reinstalling System Software” later in this chapter.

mCheck the ID numbers of all SCSI equipment connected to your computer. Your computer has two SCSI chains, an internal one and an external one. All devices on the same SCSI chain must have unique ID numbers, but devices on different SCSI chains may use the same SCSI ID number. (For example, you can have a CD-ROM drive with ID number 3 connected to the internal SCSI chain and a tape drive with ID number 3 connected to the external SCSI chain. You cannot have two SCSI devices connected to the external SCSI chain that both use ID number 3.)

On the internal SCSI chain, the computer itself has the ID number 7, and the factory-installed hard disk has the number 0. If your computer came with a CD-ROM drive installed, it is also connected to the internal SCSI chain and has ID number 3.

On the external SCSI chain, SCSI devices are numbered from 0 to 6, or 1 to 6 if you have an additional hard drive installed (its number is 0).

98Chapter 6