The LaserWriter 16/600 PS SCSI ports are not guaranteed to support all SCSI hard drives. In order to make customers aware of this, page 159 in the owner's guide has a note that reads: "IMPORTANT Some older model hard disk drives may not be compatible with the LaserWriter 16/600 PS.
Apple sells and supports a complete internal hard disk drive solution for the LaserWriter 16/600 PS. The mounting bracket and cable that can be ordered separately through service are intended only to be used for the service and support of the finished goods upgrade kit. Customers who purchase the brackets and cables for the sole purpose of installing a hard drive other than the one provided in the finished goods hard disk drive solution are on their own in the event they experience problems.
Engineering does not have the resources to test and qualify all of the different hard drives on the market. During their testing they found that most hard drives produced during the past 2-3 years work fine, but that some of the earlier drives may experience problems because they don't implement the complete SCSI instruction set. Most commonly these older drives will be 20, 40, and 80 megabytes in size.
For customers who are experiencing problems check the following:
1) Verify that the I/O controller serial number doesn't end in 34AA. If it does, replace it through normal service procedures and retest.
2) Remove the hard drive and carefully reinstall it. Ensure that none of the pins in the SCSI connectors have been damaged.
3) If the hard disk cannot be formatted using the Apple Printer Utility then try installing it in a PowerBook or external tester and format it using HD SC Setup or a third-party formatter. If the hard drive formats without any problems on a Macintosh, but fails on the printer then the drive is probably incompatible with the LaserWriter 16/600 PS. To verify the functionality of the I/O controller SCSI port install and format a hard drive from the M3297G/A LaserWriter 16/600 PS Internal Hard Disk Drive kit.
Hard drives that will not format properly or experience other problems during use are not supported by Apple. For best results customers should install the M3297G/A LaserWriter 16/600 PS Internal Hard Disk Drive.