Well, I have this UNO. I made a robotic arm for my school project. Worked successfully.
But when I returned home and started showing it off YET AGAIN to my family, something bad happened. I guess its because I touched the ATmega's connecting "legs". I realised I might've had shorted something, 'cause a got a little shock, and my faithful UNO decided to turn its back on me, after an year of service.
It refused to work, and simply refused to work out the current sketch AND receive any sketches. The ON led is always on, so is the one at D13. When I try to upload something, The RX blinks thrice, I get an error like "stk getsync not responding recv0x00" or something similar. I'm sure of the recv0x00 part, though.
I took apart 'lil ATmega from the UNO and found that after plugging the board(minus the ATmega) back into the PC, I get the exact same error.
After consulting a lot of websites and lot of guesswork, I concluded that it might be my ATmega or bootloader. What should I do now?
Here is the stuff I used:
An Arduino UNO
An analog joystick for input
Two servos connected w/ popsicle sticks for the "arm"
A 12v 1 amp AC to DC power supply brick with Arduino-able DC jack
Most likely you killed the ATMega, so the actual µC, with the shock. Static electricity is really dangerous to microelectronics.
If you have another Arduino you can try to burn the bootloader again but I am quite sure it will not help. Just go under tools->burn bootloader in the Arduino IDE. If it fails your chip is most likely dead.
At least it seems that the chip that is doing the serial communication between the ATMega and you PC was not damaged. So you can try getting yourself a new ATMega328p, insert it into the board, burn the bootloader and try again. If you do not have another Arduino you can buy the ATMega328p with the Arduino bootlader online. Should not be more than 2-3€/$
Sadly, it /does/ sound like time to replace the cpu chip.
If there were any shields connected, you may want verify they’re also still working when you get the Arduino working again.
(In the Arduino IDE) File > Preferences
Uncheck the checkbox next to "Show verbose output during: compilation"
Check the checkbox next to "Show verbose output during: upload
Click "OK"
Sketch > Upload
After the upload fails, you'll see a button on the right side of the orange bar "Copy error messages" (or the icon that looks like two pieces of paper at the top right corner of the black console window in the Arduino Web Editor). Click that button.
In a forum reply here, click on the reply field.
Click the </> button on the forum toolbar. This will add the forum's code tags markup to your reply.
Press "Ctrl + V". This will paste the upload output between the code tags.
Move the cursor outside of the code tags before you add any additional text to your reply.
Maybe the ATmega is not yet destroyed. You could look at