Hi, I'm new to the forum and since last Saturday the same problem goes here. All I found at internet was not conclusive and the only possible cause would be the bootloader, so I brought a new atmega aready burnt (with both the bootloader and the blink sketch).
It arrived, I just changed it and can't upload a Sketch.
I've checked the COM port, changed the USB Cable and tryed another computer.
The Error:
Arduino: 1.6.7 (Windows 10), Placa:"Arduino/Genuino Uno"
O sketch usa 2.554 bytes (7%) de espaço de armazenamento para programas. O máximo são 32.256 bytes.
Variáveis globais usam 115 bytes (5%) de memória dinâmica, deixando 1.933 bytes para variáveis locais. O máximo são 2.048 bytes.
C:\Program Files (x86)\Arduino\hardware\tools\avr/bin/avrdude -CC:\Program Files (x86)\Arduino\hardware\tools\avr/etc/avrdude.conf -v -patmega328p -carduino -PCOM4 -b115200 -D -Uflash:w:C:\Users\leina\AppData\Local\Temp\buildaa32fe3e4fcdb0f986372da1a629334a.tmp/LCD_Example.ino.hex:i
avrdude: Version 6.0.1, compiled on Apr 15 2015 at 19:59:58
Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
Copyright (c) 2007-2009 Joerg Wunsch
System wide configuration file is "C:\Program Files (x86)\Arduino\hardware\tools\avr/etc/avrdude.conf"
Using Port : COM4
Using Programmer : arduino
Overriding Baud Rate : 115200
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x18
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0x18
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 3 of 10: not in sync: resp=0x18
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 4 of 10: not in sync: resp=0x18
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 5 of 10: not in sync: resp=0x18
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 6 of 10: not in sync: resp=0x18
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 7 of 10: not in sync: resp=0x18
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 8 of 10: not in sync: resp=0x18
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 9 of 10: not in sync: resp=0x18
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0x18
avrdude done. Thank you.
Problema ao carregar para a placa. Veja http://www.arduino.cc/en/Guide/Troubleshooting#upload para sugestões.
Este relatório deveria ter mais informações
"Mostrar saída verbosa durante a compilação"
habilitado em Arquivo > Preferências.
Is it a clone? (Aka, eBay/AliExpress/Amazone/Chine/Banggood?) If so, it probably uses the CH340. Did you install that?
PS, next time open en new topic 
Sorry, I used this topic because it was the same problem.
Yes it's an Original Arduino Uno R3 made in Italy.
Bought It last year, on the first semester, and since my last project about six months ago, or less, that I haven't upload anything new, but that sketch still working.
Could be this?
"Overriding Baud Rate : 115200"
Obviously SOMETHING is going on with avrdude and/or a windows patch or something. You will note that all of sudden this forum is being flooded with people that can't upload. I'm one of them. I'm not a newbie, I've been working in the computer field professionally for 40 years, and working with Arduino for 5 years. I used to be a MCSE. I know all about com ports and drivers and I've tried everything I can think of. I have 6 assorted Arduino models that suddenly can't upload. They previously could. I doubt the bootloader would get corrupted on 6 boards all at once. You can see my other post in installation & troubleshooting. Need help troubleshooting, can't upload I've tried multiple boards, multiple cables, multiple computers, multiple driver versions, loopback tests, rolled back the IDE version and more. I have several projects that are dead-in-the-water because I can't upload. I've wasted about 20 hours trying to get it to work. I think this issue needs to be escalated.
That's why I still use 1.0.6 for 328, 1284, 2560, and 2561 designs.
I've read that 1.6.5.r5 is pretty good. I have it downloaded to look at files, but am not using it.
Course, depends on what hardware you're using.
CrossRoads:
That's why I still use 1.0.6 for 328, 1284, 2560, and 2561 designs.
I've read that 1.6.5.r5 is pretty good. I have it downloaded to look at files, but am not using it.
Course, depends on what hardware you're using.
I have 4(yes,FOUR) versions on my PC.
Basically, I don't like the Boards manager in the 1.6.x. It is just a difficult interface than just to paste file in "hardware" folder.
DrWizard:
Obviously SOMETHING is going on with avrdude and/or a windows patch or something. You will note that all of sudden this forum is being flooded with people that can't upload. I'm one of them.
I have quite a few Arduinos and they haven't suddenly failed. I'm not using Windows however. I very strongly doubt it is anything to do with the bootloader. It won't have mysteriously developed a bug.
I suggest reverting to a previous version of the IDE. Heck, Version 1.0.6 probably still works fine. Some earlier versions may not work with the latest Windows.
Windows has an annoying habit of installing software updates "helpfully" for you behind your back. That may be the problem.
@DrWizard: Try another PC.
If using boards like UNO and MEGA, go with 1.0.6 . It works like a treat.
Cheers,
-Malhar
This morning I downloaded the 1.0.6 and the error persists.
After compiling, the upload starts normally: the board reset, the Rx blinks 3 times, but then the Tx doesn't respond and the blink sketch burnt at the Atmega starts again with some fast blinks of the Rx led untill it gets the final error message.
Could it be a problem with the ATMEGA8U2-MU?
Should I try Ubuntu OS?
Could it be a problem with the ATMEGA8U2-MU?
I doubt it. You could try the loopback test, documented here.
You might have the wrong baud rate, the wrong board selected, a bad cable, wrong fuses. There are a lot of things you can mis-set and then the sketch won't upload.
Should I try Ubuntu OS?
I'm using Ubuntu 14.04 personally. But I wouldn't change an entire operating system to get one program to work. Unless you absolutely want to, of course. 
I doubt it. You could try the loopback test, documented here.
I've done it last night and now, and it's not passing: Tx doesn't give a sing of life.
You might have the wrong baud rate, the wrong board selected, a bad cable, wrong fuses. There are a lot of things you can mis-set and then the sketch won't upload.
Where do I find the baud rate configuration at the IDE (I've tried to change it direct on the COM port configuration but was not successful), what about checking the fuse on the board?
Well, about Ubuntu I'm checking about to do a dual boot of it alongside W10.
The board rate for a particular board type is in the boards.txt file. That needs to match the baud rate used in the bootloader. If you are using a standard Uno and haven't fiddled with the fuses, or changed the clock speed or anything like that, the defaults should be correct.
Also make sure you don't have any devices plugged into D0 or D1 while you are attempting an upload.
dmazoli:
I've done it [loop back test] last night and now, and it's not passing: Tx doesn't give a sing of life.
In my opinion, if the loop back test does not work, you can stop all other troubleshooting, and don't worry about things like baud rate and bootloaders. You must get the loop back test to work, or upload will never work. You need to find out if you're having a problem with your computer, or with the Arduino board. Do that by trying it on a different computer. Perhaps an old computer loaded with Linux would be a good thing to have around. 6 different Arduinos stop working at the same time makes me suspect the computer. Problems that could happen related to the computer are driver updates, OS updates, and anti-virus software.
dmjlambert:
6 different Arduinos stop working at the same time makes me suspect the computer. Problems that could happen related to the computer are driver updates, OS updates, and anti-virus software.
Note that there are two different users here that report a problem; only one has 6 boards failing all at a sudden (and that is not the OP).
dmazoli:
... the only possible cause would be the bootloader ...
Well, not really. Faulty USB cable, bad board, you didn't install the device driver to Windows, you selected the wrong board in the menu. There are lots of things. Millions of these have been sold, most to very satisfied customers.
Sometimes people report changing the board fixes it. So, they had a bad board. Sometimes changing the USB cable fixes it.
Sorry, I used this topic because it was the same problem.
That's like saying that when you visit the doctor you must have the same problem as the previous patient, because you are both sick.
Sorry, I used this topic because it was the same problem.
That's like saying that when you visit the doctor you must have the same problem as the previous patient, because you are both sick.
I said it at another post (in which the same error message was being showed), but then it was moved as new one.
I've tried in my laptop too and with two different cables, made my desktop run with a dual boot to try on Ubuntu and the problem persists.
Now I've tried changing the Baud Rate of COM port to same on boards.txt file. Before the transfer rate was 9600, now 115200, but none works.
If you cant get the loop back test working, consider buying a FTDI breakout board.
