before you take to pieces i suggest you boot of floppy disk if you have bootable copy of dopus if you dont i can make you one .
with 6 hds going make tricky to work out which is the boot hard drive the guy hasint made easy for you . am assuming you are not to fimilar with amigas ?
well the 4000 esp u chould try booting with no start-sqwence and just let machine do its thing for at least hour see just one the hd needs to check iself sounds like the boot drive is .. try listen for which drive making the sound and then try disconecting the others or just maybe disconect the power cables to them that way you wont get ide cables around the wrong way .
If you boot of a program floppy you can check what hds are showing up and check to see with hdstepup that your main wb partion well any is set to be bootable
if booting from floppy i whould not start pulling cards out the system willie nillie
how i blew up my amiga 4000 desktop well not to panic i shorted out the floppy and assuming did someting to the psu so always pull out the power cable or switch it of at the switch, i was in hurry had visters call in aghhhhh
the cdrom light always being on chould mean one ide cables is pluged in wrong side around try reversing it it wont damage anything if wrong so dont worry
the 4000 t is it scsi only or ide too i assume its both ?
if its just scsi system try booting from floppy as above steps
let me know how u get on