Arduino Uno R3 not recognized by computer, TX and RX not blinking, neither are lit. Is it dead? I was trying to make my arduino uno r3 to work on my Linux machine (including the IDE), but it wouldn't. At first I thought it was a software problem. Added myself to different groups and did everything, people discussed on the forums. It didn't work. It wasn't recognized by the computer at all. I reinstalled. Nothing again. Thought it was a hardware problem of my computer. Tried with dad's (Windows 7 machine). Didn't work. Then I saw that the two leds (TX and RX) are not blinking, neither are lit. I started doing a research on the internet but everybody suggests doing the loopback test from the IDE. My Arduino Uno R3 is not recognized by the computer, therefore the IDE. Is there any way to check if it's dead or if it's a minor problem?

Edit: I read a lot on the case last night and I reach to the conclusion that my ATmega16u2 (the usb-serial chip, I'm sure it is 16u2 and not 8u2, it's written on the chip itself) might be dead. Tried to reflash the firmware but cannot get it in DFU mode (as it says in this article click here). dfu-programmer (the Linux application) throws the following error: dfu-programmer: no device present. What to do?
There is a chance that your bootloader is not working anymore. You can burn a new bootloader to the device with another Uno, there are nice guides on the Arduino-Website.