When the computer turns on the boot rom in the controller will start looking for a hard drive to boot from (which will be in the range 0 to 6).
It's possible that without a drive plugged in or if it's unable to communicate with the drive (maybe a bad scsi cable) then the boot rom will sit there for a long time just in case it comes on eventually.
At the moment I do not have an extra scsi cable so I have to wait before I try that as well. However I did discover something else which I do not know if it says anything about where the fault might be...
The hd8 has two LED lights; one green and one yellow with the yellow LED showing hard disk activity. Now, when no scsi cable is connected to the hd8 only the green LED turns on. When I connect the scsi cable to the hd8, but no hard disk, the yellow LED turns on and off repeatedly. When I then connect the hard disk, again only green LED turns on.
Does this mean that the controller is indeed finding the hard disk and the problem might be something that happens afterwards?
I will try a new scsi cable the moment I have one just to make sure I try any option.