Hi,
I've recently got an arduino UNO. And it was working fine.Now I may have accidently plugged 12V straight into one of the digital pins that were an output. Now my board doesn't work? I can't upload to the board. The green LED does not turn on unless I angle the usb, but I the board can still be detected as a port on my computer? Any ideas on how I can get it to work again ?
Don't know man, Its most likely that uve fried it..
But I may be wrong too...
zemark:
Now I may have accidently plugged 12V straight into one of the digital pins that were an output.
How did you accomplish this? I ask out of curiosity and as a troubleshooting step to understand what kind of damage could have been done. You likely destroyed the I/O pin of the ATmega. I'm not sure what you by "plugged straight into." That sounds like an intentional action, not an accidental one.
zemark:
The green LED does not turn on unless I angle the usb, but I the board can still be detected as a port on my computer?
This implies there is a loose connection, but that seems like it would be unrelated to applying 12V to an I/O pin.
When connected by USB, the Uno gets power from USB. So none of the on-board regulators are used. The 8u2 handles USB while the ATmega is where your code runs. If the computer is recognizing the Uno is attached then the 8u2 is still working. If uploads fail, you have likely burned up the ATmega which will need to be replaced.
Um I had a few relays and the Arduino all connected on a breadboard. However the relay needed 12V to switch it. So I was intending to move the wire from the 12V supply from one breadboard pin to another but accidentally touched the wire connected to the output of the Arduino.
Oh ok fair enough.
At the time of plugging the 12V into the pin, I was only powering the Arduino from a 9V battery. Is it possible to get replacements for the ATmega? Additionally, the RX and TX leds do not light up during upload anymore.
Well, when you are in a puddle of mud pondering over what hit you precious Arduino, mostly its because you supply 12V to the arduino pin. So it catch over-current.
Anyway, take your board and check the black circle-marked fuse on it. Now take a solder iron and softly put a drop of solder material on it and you are good to go again. Your board will no further have any on circuit over-current protection. But, it will work as normal.
Other than this, the reason for a burned out board may be the burnt ATmega chip.
If your ATmega is removable, remove it. See if the board powers up.
take your board and check the black circle-marked fuse on it
What Arduino boards have anything marked Fuse on them? Your advice doesn't really make sense. Unless you are talking about the poly fuse, but that isn't marked as you have indicated. And it is only used when connected via USB.