Ok, back to the problem... I had a few days off and tried something else to solve the problem.
I got me another Laptop HD and connected that one. It spun up, but it "stuttered" at some moment as it slipped a little lying on the empeg casing (obviously didnt install it just connected it). This seems to indicate that it actually IS a cable or connector problem, as the disc was definetly actuated but it wasnt recognized while empeg powered up.

Thats going to be next on my list of "to do" things, I'll keep you guys informed