Yup. That kinda points to a cable/connector issue.
The internal bracket is probably good, though if you had a spare I'd say to switch to the spare.

The external cable is an eSATA cable -- different connectors on the ends than a regular SATA cable, so keep that in mind when hunting for a replacement.

If you don't have them locally, I could always send you a new cable set, but I dunno if that's worthwhile or not (borders).

Cheers