Now fully convinced there's something wrong with the nand-x. Resoldered, checked continuiy, even checked continuity from the motherboard to the nand-x connector that plugs into the nand-x, all good.
When I try to read nand I still get "Looking for USB interface device, no device found" error.
Tried on a different computer same thing.
Unplugged the nand-x completely from the computer and hit read nand again, exact same error message.
There is a disconnect between the nand-x and my motherboard. As I mentioned, I've already ordered a nother one, but if anyone has encountered a similar issue and was able to resurrect the nand-x, please let me know.
Please don't post anything about soldering.