Cannot connect MyBook Essential 2TB / Live 3TB

I am having issues with two products. One is a MyBook Live 3TB and the other is a MyBook Essential 2TB.

They were purchased less than a week ago with the intention of being removed from their enclosure and used as internal drives or in a different external enclosure.

I am running Windows 7 Home Premium 64-bit.

The good: Both are recognized by the OS when connected via onboard SATA. The 2TB can be formatted and works properly via SATA.

The bad: Both drives are unrecognized when connected via USB. The SATA>USB converter, cable, and USB ports have been tested since attempting use with these new WD drives and they work properly with other, so that rules them out as a suspect. When connecting the 3TB via SATA, any attempts at formatting will cause a BSOD. I’m aware 3TB drives need to use GPT, which I am able to do, but any attempt at formatting the drive causes an error. Have tried booting into GParted and formatting that way using GPT/NTFS, but it is still unrecognized by the OS.

I’ve scoured Google and many forums for answers, to no avail. Any help would be greatly appreciated.

Just thought of something. The SATA>USB converter is from a 2.5" enclosure. Perhaps it doesn’t pull enough power to run 3.5" drives? It has to be plugged into two USB ports, but maybe that’s still not enough? I swear I thought I’ve used it with 3.5" drives before but I could be wrong.