Delay blink not correct

hi all,

I buy my first arduino uno and after unboxing I have my first problem ! :slight_smile:

I wanted to upload the blink sketch from the exemple. But the led blink is not correctly!
As I am not good on english explication I upload a video on youtube.

I use arduino on mac 10.9

I know you said you used the example code, but can you post it anyway, exactly as uploaded?

Also maybe try a loose LED on another pin? (Don't forget the series resistor to limit the current.)

I test with a basic code

int led = 13;

void setup() {                
  pinMode(led, OUTPUT);     

void loop() {
  digitalWrite(led, HIGH);  
  digitalWrite(led, LOW); 

OK after multiple test I found this :

  • The sketch run correctly only if arduino is pugged on external source or on windows via vmware
  • Abnormal executing from any sketch and any pin If connected on my mac. Even close arduino app and unplug/plug arduino
  • Impossible to upload skech via windows (vmware) error avrdude: stk500_getsync(): not in sync: resp=0x00

My problem is resolve after formatting !