Hey!
I have school project coming so i was testing my LED stripe Arduino project. But i managed to over voltage Arduino. After that Arduino started to smoking and it never turned on... So is there any chance that i can fix it? Because i do not want to buy another Arduino and make my wallet cry again 
Thanks for the help guys! UPDATE! If i power arduino trough the LED strip then it turns itself on a second.
You can try replacing just the Atmega328P chip, but there's a chance you damaged the USB/Serial chip near the USB connector.
Remove the 328P, and try the Loopback Test at the top of this forum.
If that works and you have 5V and 3.3V on the Power header, try replacing the 328P. You can get a bootloaded part here for just a few dollars. Get a spare while you're at it.
If the other stuff doesn't work, then you're out of luck, get another board.
Or consider a Promini and a FTDI Basic.
http://www.dipmicro.com/store/index.php?act=viewCat&catId=595
I took the 328P chip off and tried loopback, but my PC did not recognized Arduino. So this means that Arduino is done? Sorry im newb in this electronic world.
"So this means that Arduino is done? " Pretty much. Sorry.
Yeah, it's done for.
It's sort of silly how they have the DIP socket for the '328p - when the non-replaceable 16u2 is usually what goes. It seems particularly fragile w/regards to abuse of the power rails - you never hear of a CH340G-based clone losing just the serial adapter, while that's a common failure mode in 16u2-based boards.
Guys, today my arduino just WOKE UP! How is this possible?