No COM

Hello,

I'm new to everything Arduino and programming... and electronics in general... so bare with me in my attempt to resolve this issue. I've been using my Arduino for a few days now and now I can't use it at all. It started with intermittent COM 9 not found problems. I resolved them by simply unplugging and re-plugging the Arduino a few times. All of a sudden today, there is no COM at all... Connection is fine physically. (as far as I can tell... board is receiving power and a previously loaded sketch is running). When in the device manager window, not only does the Arduino not appear, but there are no com or ltp ports listing at all, even when viewing all hidden devices. The serial port is gray when in the tools menu of the Arduino IDE. I've gone through ALL troubleshooting tips on the websites. I have even totally uninstalled everything and reinstalled it. No luck... any help?

Thank you in advance, really bummed I cant do any work with the Arduino...

I'm running vista, and have an Arduino Uno (bought it labled as R3 but I believe its actually R2) if that information is relevant

p.s. its not a usb hub problem because I can connect other usb devices no problem

Just to add some information that might be relevant, when I plug in the Arduino, the Tx and Rx do NOT light up at all. Is this normal? I read that they turn on for a very short amount of time no matter what when it is plugged in via USB.

I will keep you informed, although as of now I have received no information. Luckily I bought my Uno very recently and can still return it, so I'm going to get a new board and see if it was a board hardware issue.

just an update, I sent my Uno back and got a replacement from a different company (still a true Arduino board though, just a different seller) Plugged it into my computer and it worked right away... so i guess that means it was a hardware issue on the board itself

Yes! when you see that the power on led is not switched on even while connected to the USB port, its the USB host adapter problem in the board. cheers. enjoy