"avrdude: verification error, first mismatch at byte 0x0000" while uploading

Hello,

I recently changed the extended fuses to 0xFF on an Arduino Uno R3 SMD using this programmer(goo.gl/UnMTwK) with the command "avrdude -c usbtiny -p m328p -U efuse:r:-:i -v". When I try to upload a sketch I get the following error:

avrdude: verification error, first mismatch at byte 0x0000
         0x62 != 0x0c
avrdude: verification error; content mismatch
avrdude: verification error; content mismatch

I also tried to upload the blink sketch but it didn't work.
I googled the error and I understood that there is a problem with the bootloader and that I have to change it or re-install it, but I have to clue how.

Any help is appreciated.

After some research, I found out that you can upload a sketch through the programmer without using a bootloader. I tried this and it worked almost fine. Sketches like the 'blink', the LCD 'Hello World' work flawlessly but when I try to upload the sketch I want it fails. The sketch that I want to run basically outputs a string in the first row of the LCD screen and a series of calculated numbers in the second. Uploading this sketch doesn't output any errors, but instead, only the first row is displayed. Then I tried to output the calculated numbers in the first row and the text in the second. The result was that the first row was empty and the second normally displayed the string. The only two causes that I could come up with are that the sketch is large(4,994 bytes), which is probably not the cause and that the voltage is too low. The voltage supply is at ~2.8V.

Any help appreciated.

would you mind pasting the code?
maybe there is some bug in the code...

did you try to burn a new bootloader on the broken uno?
you need another arduino, or a isp programmer.

what programmer do you have?

Thanks for answering, I changed the fuses with the usbtiny programmer to Extended:FF, High:DE, Low:FF. The only difference from the standard is that I disabled the Brown out detection. I uploaded the sketch through the programmer, because otherwise I had the error of non existing bootloader. I searched around on how to install a new bootloader but I couldn't find any newbie guides. The sketch that I am trying to run was running perfectly previously so I doubt there is a bug.The sketch was made to test if an Arduino functions properly. It does that by doing four tests. One for conditional operations, arithmetical, SRAM and flash. Below are the two latter tests:

void run_flash_test()
{
  for(int repeat=0;repeat<1000;repeat++)
  {
    //flash_check
    for(unsigned char i=0;i<16;i++)
    {
      flash_check=(flash_check ^ svalue1) + svalue2;
      flash_check=(flash_check<<((svalue3+flash_check)&7)) + (flash_check>>((svalue3+flash_check)&7)) + svalue4;
    }
  }
}

void run_sram_test()
{
  for(int repeat=0;repeat<10;repeat++)
  {
    //SRAM check
    for(int i=0;i<2405;i++)
    {
      value1=(value1+value2+value3+value4+sram_check)&1;
      value2=(value2+value1+value3+value4+sram_check)&1+1;
      value3=(value3+value1+value2+value4+sram_check)&1+2;
      value4=(value4+value1+value2+value3+sram_check)&1+3;
      sram_check=(sram_check<<1)+(sram_check>>7)+value1+value2+value3+value4;
    }
  }
}

The sketch was written by Svarichevsky Mikhail, not me.

When everything works fine, it outputs specific values for sram_check and flash_check on an LCD display. If the screen displays some other numbers, then something is not right. But in my case, nothing is displayed on the screen.

if you have a programmer, you should try to burn the bootloader to the arduino:

in tools > programmer select the programmer (USBTiny) and in the boards section, select arduino uno. then click tools > burn bootloader

why did you changed the fuses?
here is a short lecture about fuses: AVR Tutorial - Fuses

I created another topic that discuss the same issue. There I give more details: Difference between 0xDE and 0x:D6 (high fuses) - Microcontrollers - Arduino Forum

Thanks for helping

I have a problem with a Uno R3 that will not work, when I say won't work I mean it will not accept any code. The error is the one about errror at byte 0x000? I also receive a" avrdude: verification error; content mismatch"
This error even happens when I try to run the blink sketch.
I have looked and looked and every where I do I find either how to download etc. I have xloader installed but it won't do the trick. My problem everyone says to load the "hex" file. Simple question where do I get the hex file. People point github but I am unsucessful trying to find a arduino hex file there. If someone could point me to where to find it, it would greatly appreciated.

The hex file is uplo

sooner1949:
I have a problem with a Uno R3 that will not work, when I say won't work I mean it will not accept any code. The error is the one about errror at byte 0x000? I also receive a" avrdude: verification error; content mismatch"
This error even happens when I try to run the blink sketch.
I have looked and looked and every where I do I find either how to download etc. I have xloader installed but it won't do the trick. My problem everyone says to load the "hex" file. Simple question where do I get the hex file. People point github but I am unsucessful trying to find a arduino hex file there. If someone could point me to where to find it, it would greatly appreciated.

Post the full text of any and all error messages, not your paraphrasing of them.

The hex files are generated as part of the upload process, transparently. You can also get them with the export compiled binary option. But it's usually easier to let the IDE do the upload process for you.

"avrdude: verification error, first mismatch at byte 0x0000 0x62 != 0x0c"

I started getting this error from one of my UNO boards...the genuine one from Arduino.cc, in fact. It started suddenly when I was uploading sketches repeatedly in development/troubleshooting stage.

My fix was to "Burn the bootloader" as in this tutorial > https://www.arduino.cc/en/Tutorial/ArduinoISP entitled "Using an Arduino as an AVR ISP (In-System Programmer)". This worked for me because I had another UNO board with a 22uF capacitor at hand. (I guess the 10 uF value advised by the tutorial is not a real critical value.) Undoubtedly, the bootloader was corrupted from normal upload activity, at least normal in the sense of it being done by imprecise humans. Or maybe the corruption had nothing to do with my technique. Who knows?

Anyway, happiness is having a spare UNO around, believe you me!