Does Nano not get sufficient power via USB?
I have a few clones but have not seen this behaviour so I guess it could be one of three things (in order of most likely to least):


They have a fault related to taking power from the USB connector.
The USB lead is not able to supply enough power ie. it is cheap and extremely thin and cannot carry much current. Have you already tried other cables?
Your USB port cannot supply enough power. Given that the spec says 500mA from a USB 2 port, this seems unlikely unless the port is faulty. Have you tried other ports / another PC?