mantoui:
Buyer beware. I have a working nano from gravitech, but ordered an "Arduinno nano 3.0" from amazon. After a few weeks, it arrived from shenzheng, china. It ran a few sketches, but after an hour it no longer worked. Multimeter showed only 0.015v on Vin? (running from USB),That would be normal when powering via USB, Vin is for supplying external power ( +7-12 V) to the board for running when not attached to the PC's USB port.
and initially 5v (pin 27) showed 4.8v,
That also is about normal, the USB +5vdc goes through a isolation diode (shockley type) that would account for a .2vdc drop.
but now it shows only 2.6v and the USB is no longer recognized by PC. sigh. you get what you pay for.
That is not normal. Have you tried another USB cable? Some of those cheap USB cables can be flaky.
Others I see have complained about Amazon selling units as Arduino, when they are in fact clones.
Well I believe the arduino company licensed only Gravitech to actually build and market the nano board and I don't see it listed on many of the normal retailers that carry other 'official' arduino boards. It's a little pricey in this day and age at $35 (Arduino Nano 3.0 with ATMEGA328 ) compared to the other 328p boards. But it certainly is a nice complete little board (on board FTDI usb, on-board 5 volt regulator, ICSP connector, full leds (power, L13, tx, rec) so it gives up little over the normal Uno type boards except for lack of standard shield connectors. And even there the clever Asians have come up with a clever solution for that, ( http://www.ebay.com/itm/170898217204?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649 )
So I think the Asians have taken over the Nano market as they are selling them in the $10-15 by the thousands on Amazon, E-bay, deal extreams, and even direct ( http://www.fasttech.com/products/1008/10000015/1001002-arduino-nano-v30-atmega328p-20au-board ) , so anyone selling one much under $35 is bound to be selling a clone version rather then one built by Gravitech.
Again check that USB cable
Lefty