No LED blinking, no power on when plug in to USB

Hi, I just got my new UNO R3 board, when I connected to the USB port, the board didn't turn on the power on LED. No flashing LED, I don't even hear the USB tone's sound whenever u plugged in an USB device. It didn't show USB device detected msg box, no "unknown USB device detected" msg box appear at all. The board is seem just death when plugging into USB port. But when I power up using external power source, the board able to power up and I can see the power on LED turn on.

I am using Levono ideapad y550 laptop. When I browse my device manager, I don't see port(COM & LPT) device in the list.

Hi, I hade the exact same problem. No power led, just completely dead. I was completely sure that my Uno was faulty but as a last resort I tried with a different USB-cable and it powers up just fine.

Power led is on and everything seems to work normally.

senilo: Hi, I hade the exact same problem. No power led, just completely dead. I was completely sure that my Uno was faulty but as a last resort I tried with a different USB-cable and it powers up just fine.

Power led is on and everything seems to work normally.

I tried 3 different USB cable and result is still not working. Very sure it dead. Anyway I had bought another UNO and it working perfectly. You are lucky that it USB cable problem, not the board problem !

Have u tried using dc adapter.............. because the one i got also have same problem ....... there is no capacitor between usb port and regulator in arduino .......