WalterPG,
Inspiron 660 USB ports =
Front Two Black USB 2.0
Rear Two USB Black 2.0, Four Blue USB 3.0
So initially you installed the 1TB HDD+SIIG model JU-SA0212-S1 enclosure inside the chassis and routed the cabling to the rear of the system and plugged it into one of the blue USB 3.0 ports?
Can you test the 1TB HDD+SIIG model JU-SA0212-S1 enclosure on the same USB 3.0 port that is working for the docking station?