Can't reset Atmega16u2

Hello!

I purchased Arduino UNO R3 like week ago.
I intalled drivers, IDE etc, and everything works fine for me, I could update programs, and whatever i wanted.

But one day i could't update my program due to:
avrdude: stk500_getsync(): not in sync: resp=0x00
error.

I readed a lot about this problem, but like other people, i hadn't to find anwser.
I bought USBasp today, and I updated manually bootloader.
I can update programs via programmer(USBasp).

I came to the conclusion that something with Atmega16u2 is wrong, so I had decided to update firmware on this.
I followed this guide:

but problem is when I shorts GND and RESET pin it doesn't react.
I still can see Arduino UNO on Printers and devices.

My arduino doesn't pass Loop-Back test.

Any ideas?

Thanks,
John

It boot loader crash problem.You selecthttp://www.rhydolabz.com/index.php?main_page=product_info&products_id=597
and try to upload boot loader using below steps.
and use burn boot loader option from tools

I updated bootloader, but this doesn't change anything... =(

I bought today new atmega328P-PU with arduino bootloader included.
It's still not working as well....

IMO it's definitely atmega16u2 fault.

folfix:
I updated bootloader, but this doesn't change anything... =(

Usually similar kind of problem i faced when taken new arduino board. I have done uploading bootloader using Avr programmer. Have you getting any error while uploading bootloader. Please share step in screen shot how you being updating bootloader.

Another question here have you tried to upload program with infinite loop in Arduino before the error has been raised???
R u connecting any Tx and Rx peripheral while uploading???

This board is new, but not that new, as you think. I used this few days, without any problems, i updated programs without problems, and i don't know what's happend. As i wrote, i bought new atmega328 with arduino bootloader, and it was tested, so it's not problem here.
All pins are disconneted, Tx Rx too.

folfix:
This board is new, but not that new, as you think. I used this few days, without any problems, i updated programs without problems, and i don't know what's happend. As i wrote, i bought new atmega328 with arduino bootloader, and it was tested, so it's not problem here.
All pins are disconneted, Tx Rx too.

As i wrote, i bought new atmega328 with arduino bootloader, and it was tested, so it's not problem here. What does it means.
Which is last program you have update?? is it contain infinite loop???

It mean:
I bought Arduino Uno.
I worked with it like 2 days, and everything worked fine.

CRASH
I can't update any program because of avrdude: stk500_getsync(): not in sync: resp=0x00 error.
I tried find way to repair it.
I thought it's atmega326p crashed, and i bought new one.
I took this one with Arduino bootloader included, and i noticed it include Blink program(L led blink when i connect power to board).

When I try to upload any program, only USB cable is pinned.

The problem is:
avrdude: stk500_getsync(): not in sync: resp=0x00
error.
And this is major problem.

This was my last program:

#include <LiquidCrystal.h>
float temp = 0;
const int tempPin = 0;
const int buttPin = 7;
const int ledPin = 8;
const int button = 9;
const int speaker = 13;
boolean pozycja = 0;
boolean stan = 1;
boolean guzik = 1;
int licznik = 0;


// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup() {
  pinMode(buttPin, INPUT);
  pinMode(ledPin, OUTPUT);
  pinMode(button, INPUT);
  pinMode(speaker, OUTPUT);
  lcd.begin(16, 2);
  lcd.display();
  analogReference(INTERNAL);
  
}

void loop() {
  
 
    guzik = 1;
    do {
     pozycja = digitalRead(button);
     if (pozycja==1){
      lcd.clear();
      lcd.print("  SCREEN  HOLD");
      if (guzik == 1){
      digitalWrite(ledPin, HIGH);
      while(pozycja==1) {
        pozycja = digitalRead(button); 
      }
      guzik = 0;
      } else if (guzik == 0){
      digitalWrite(ledPin, LOW);
      while(pozycja==1) {
        pozycja = digitalRead(button); 
      }
      guzik = 1; 
      }
     }
  } 
  while(guzik==0);
  

    
    
  stan = digitalRead(buttPin);
  if (stan==1) {
    digitalWrite(ledPin, 1);
    stan = digitalRead(buttPin);
    lcd.clear();
    lcd.print("SENSOR ACTIVATED");
    
    digitalWrite(speaker, 1);
    delay(50);
    digitalWrite(speaker, 0);
   
    delay(6000);
    digitalWrite(ledPin, 0);
    
  lcd.setCursor(0, 0);
  lcd.clear();
  lcd.print("  TEMPERATURY" );
  lcd.setCursor(0, 1);
  lcd.print(temp);
  lcd.print(" ");
  lcd.print((char)223);
  lcd.print(" Celcius");
    
    
  }
  
  int zmiana = temp;
  temp = analogRead(tempPin) / 9.31;
  licznik++;
  
  if (zmiana!=temp) {  
    if (licznik>5000) {
  lcd.setCursor(0, 0);
  lcd.clear();
  lcd.print("  TEMPERATURE" );
  lcd.setCursor(0, 1);
  lcd.print(temp);
  lcd.print(" ");
  lcd.print((char)223);
  lcd.print(" Celcius");
  licznik = 0;
    }
  } else {
    zmiana = temp;
    
  }
  
}

Last program which I updated is working.

folfix:
It mean:
I bought Arduino Uno.
I worked with it like 2 days, and everything worked fine.

CRASH
I can't update any program because of avrdude: stk500_getsync(): not in sync: resp=0x00 error.
I tried find way to repair it.
I thought it's atmega326p crashed, and i bought new one.
I took this one with Arduino bootloader included, and i noticed it include Blink program(L led blink when i connect power to board).

When I try to upload any program, only USB cable is pinned.
[

Have you tried upload the programmer using Avr pocket programmer./ boot loader.

I have tried upload via this


without effects.

Have you tried it again. What error your are getting. can you put image

After click Burn Bootloader, i had wait few second, and that i’ve get:

http://wklej.to/el2jH

4.png

Which programmer ur using for uploading boot loader.
You have not printed result after boot looader being updated??
meant to say failed result or success result

USBasp
It had not print.
But I am sure it has success result.

USBasp
It had not print.
But I am sure it has success result.

What didn't print .???

But I am sure it has success result???How you are sure about it??