Arduino Uno won't turn on

I've had my Uno for about a year now, so I am still a beginner, but I can not find an answer anywhere and I am hoping I do not have a broken board. My Arduino Uno will not turn on. I recently transitioned from Windows to Linux, so I thought maybe the computer simply did not recognize the board, but even if I plug into an external power source it still doesn't do anything. I know power is making it to the Uno, because it is getting warm, but the power light does not come on and I can not upload my projects to it.

please help

mo510108: please help

If the LEDs aren't coming on at all, that's a pretty sure sign your board is damaged. Sorry. If you have a socketed Uno you may be able to replace the chip. But it depends what has failed.