Arduino uno stopped working. Led on, cant be found in devises or port.

Development Tools IDE 1.x
1

windows 8
arduino one (not smd)

I was able to uploade code, and test out things on the breadboard for 16 hours. Disconected board for 2 hours and now it doesnt registeron the computer anymore. computer gives it power but i cant find it in devices.

The green LED is on, but doesnt react to me pushing the reset button.

before 2 hour break, i plugged in 12v ac-dc powercable. everything went fine, did what it was seposed to do.

I also used pins 0-12. 0-8 led grid, with resistors 330 Ohm resistors. 9-12 push buttons with 10k to ground.

fear that my arduino is dead, if so: what is the best replacement.

2

That 12v ac supply sounds like the culprit.

Your atmega chip can simply be lifted out (just a small screwdriver or flat bit of a knife) from it's socket.

3

Robin_Nilsen:
before 2 hour break, i plugged in 12v ac-dc powercable. everything went fine, did what it was seposed to do.

Next time don't plug anything over 9V that's the safest limit, and be sure the power source is a switching one.