So cgminer does see it, its just not responding. Why?
Im sure this is a defective device now. If the other one works, then this should to, or at least get detected.
Couple question: Per the first post, are you running stock cgmining or the version with drivers for these? (-vh)
If you're running with -vh, did you compile with --enable-gekko?
Only other thing to try is tweaking voltage to see if it fits upon insert because port can't handle power . draw. If you have multimeter that helps to troubleshoot but you can blind turn the pot to adjust voltage