Vantec EZ-SWAP4 issues

[Alfy]

Hi All, Was wondering whether someone might be able to help me with an install issue that I'm having with the EZ-Swap4. I installed per instructions but doesn't detect either of the two drives that I've put in there. I've tried Western Digital 1.5TB W15EAS and a Western Digital 640GB WD640AALS. I'm using a Asus P5N32 motherboard with 6 SATA slots. It seems to make good contact when I shove the drive into the slot. When I power up the machine the bios doesn't detect the drive. The fan rpm indicator on the EZ-Swap briefly shows 100rpm and then goes to zero with the fan icon blinking(I think this may be normal since the temps show 20deg C). I've tried multiple Sata cables. Tried plugging into different Sata ports on the mother board. Scanned the various settings in the bios etc. When I plug the drives directly into the motherboard they are detected without issue. Hopefully this is some easy rookie mistake that I've made... At this point, I'm wondering whether the convenience of removable drives is worth the hassle! Thanks in advance for any suggestions.

Regards,
Mark