I just purchased a retail Sony DRU-870S sata and had the same problem - but - on just testing in another newer machine found that it worked just fine. Upon further checking it turned out the SMPS in the regular machine was not upto scratch and couldn't safely supply power to more than 2 sata drives! Therefore, if you get a chance, test it in a different system (preferably a newer one) and see whether it works.
(BTW the original machine on which it was installed had an 'Enhance' PSU rated at 450W but it was not providing that according to a service engineer. This seems to be a common occurrence).
Some food for thought....