I'm using win-xp,arduino uno R3, and it was working ok, until I ,by mistake, applied a 12v on the 5 v pin (for only a second maybe) now I can't upload sketches, it says:
avrdude: stk500_getsync(): not in sync: resp=0x00
notes: -now when I press reset button the led doesn't blink like before(it's always on). -green led is also on. -my pc still recognize the ardunio(arduino com6...)but only when I remove the atmega328. -the 5v pin and 3.3 v pin, both don't give the voltage they supposed to,I removed the atmega328 and measure the voltage out of them and both give around 3v(3.09 exactly). my guess : atmega328 is damaged. so,what if i buy a new one, would it work or there might be other problems like crystal damage or any other components on the board?should i consider buying a new arduino board?