Are you referring to true "lack of detail" or is the apparent softness the problem?
Scans straight out of the scanner are soft. Usually, the best workflow is to scan with all internal scanner sharpening set to zero and massage the files in post.
Bruce Fraser recommends a three step sharpening process, input sharpening artistic sharpening and output sharpening.
The digital workflow, which is what you have entered as soon as you scan, REQUIRES sharpening as part of the process. It is not a flaw or aberration.
All that said, yes... there could indeed be a problem with the mechanicals. The scanner may be off, the shot may have been soft, the camera may have moved or the subject may have moved.
have you been getting consistently good results before this episode? Is this the first time you have ever used the scanner? Do you have a known good test negative or chrome?
There are a lot of variables and you just have to pin them down one at a time.
Tom