Last week I retried some of my Arduinos and one Mega was working without a problem, but two Uno's didn't work anymore. The error I got was something like:
avrdude: stk500_getsync(): not in sync: resp=0xyy
Where yy where all different kind of values (I cannot copy/paste it as I'm not near the Arduino's).
Does anybody know where to find a document what the response values mean?