Work from the bottom up:
* Does all units have correct power? +5V +12V
* Do the controller have termination and the last unit?, and everything else is without.
* Is termination power removed from all but the last unit? and of the correct polarity? (some braindamage designs out there!)
* Do all units show up with correct ID and LUN in your software SCSI tool (booting from floppy) ?
* Is the correct driver for harddisc (scsi-hdd) and cd-rom (scsi-cd) being used?
* AmigaOS makes use of these drivers?
* CD-disc is of iso9660 format?
* Filesystem driver is iso9660 ?
* Can you list any directory from CLI ?
(once again reminded why computers can be a pain in the ass

- but M$ is just pain

)