Hi!
I have received my U3 yesterday.
Unfortunatly the U3 will not work.
1. Plug in Power
2. Plug in USB
3. Device is recognized and installs CP2102 Driver
Starting cgminer --benchmark ( Ver. 0.4.9.1 ) No Device found
Starting cgminer --benchmark ( Ver. 0.4.6.1 from bitmain HP) No Device found
Replacing U3 with a R-Box or New RBox and there are no problems, cgminer is hashing
Is my Bitmain U3 DOA?
Use Zadig to replace the driver with WinUSB driver. Don't expect much reliability from the U3, but you should at least be able to get it to work for a little while.