Arduino Nano V3.0, no power through usb

Hi,

I am a little new to arduino and to electronics in general. I have been playing around with my arduino and getting used to it. Today I tried to load a new sketch on but when I plug in the arduino to the computer with a usb it doesn't turn on. If I power it externally and then connect it to the computer the computer says "USB Device Not Recognised". It was working fine yesterday, when I loaded the Hello World sketch for LCDs. I have tried it on all the different usb ports on the computer, and on a different computer so its not the computers fault. I have used more than one usb cable and they work fine with other devices.

Does anyone have any idea what could be causing this?

Thanks

Sounds like a bad connection between the USB power lines and either +5V or Ground. You should get a multimeter and probe around to see how far the +5 from the USB cable is getting. Good time to learn to read a schematic. :slight_smile:

Thanks for the suggestion. It seems that there is a problem with the USB FT232RL