I have recently been having issues with my Arduino Uno R3, just about around the time I got Avast! Antivirus. The actual problem is, when I try to upload the Blink sketch, I see the "Done Uploading". Naturally I assume this means the board was programmed properly, but the onboard and external LEDs do not flash like they are supposed to. The external LED just won't light, and the on-board LED lights, but if I put a jumper into pin 13 (not connected to anything), it goes out. My version of the Arduino IDE supports sketch verification (not sure if it is on all versions), and when I verify it I get this:
avrdude.exe: verification error, first mismatch at byte 0x0000 0x0c != 0x62avrdude.exe: verification error; content mismatch
Weird. So I tried the loopback test, and it echoes fine when I use PuTTY, but when I try the Arduino Serial Monitor, nothing happens. When I try it on PuTTY after using the Serial Monitor, nothing happens. Either way, I see the RX and TX LEDs light for about half a second, then go blank. I have also tried shorting the first two pins on the header closest to the reset button, which is supposed to reset the 16u2, and the Arduino disconnects from the computer, but after that Windows plays the "Device Unrecognized" sound until I unplug and plug it back in. I do not have an external programmer to use with my Arduino, unless I can use the Raspberry Pi to do this. By the way, here is the code produced by the IDE when I try uploading, which I got with the verify option: Link (was too big to paste here)
Any ideas? I am afraid that my Arduino might be bricked, as the 16u2 chip feels slightly warm (could just be me though, I am a little bit sick right now).