Actually, your SCSI drive may not need replacing.

My SE from 1987 did the exact same thing; boot it up, but question mark icon. So I ordered a replacement drive...which prompted the same reaction from the SE. 'No disk' icon. I think I ended up replacing the floppy drive in that one too, but even when it did accept disks, neither HDD would show up. So I figured that they were trashed.

But then I booted up my Centris 610 and ran my OS 7.6 CD. From that CD I pulled Apple HD SC Setup. I then transferred it to an 800k floppy disk, and on that same disk I added a very chopped-down System (due to limited room on the disk), which I then loaded into the SE. The System caused the SE to boot off the floppy disk, and then I ran Apple HD SC Setup. And presto! The drive works! It just needed initializing.

I forget which hard drive is in that SE now; the original one, or the one I ordered...but anyway, the one that's in that SE now didn't work, as if the drive weren't there, until I ran Apple HD SC Setup on it.

So I don't know if the same will apply to you or not, but there's my success story...

Good luck!

-Apostrophe