I compared the SCSI boards in this S1100 and my S3000XL and can clearly see the fuse in the latter so I guess the S1100 doesn't have one, despite what the blog suggests! No matter, I took the SCSI board out and reseated it which luckily solved the problem.
As well as fully expanded memory, this S1100 also came with a digital in/out option and OS 4.3 onboard so I think I've done pretty well with this buy. All I need to do is fit a new backlight (already ordered) and it'll be tip top.
Cheers,
Craig