Arduino code will upload on the board but will not run

Hi, @marc571b22
Welcome to the forum.

To add code please click this link;

As @JohnLincoln has explained.

Try this in your loop;

void loop()
{
digitalWrite(13, HIGH);  // turn on LED
delay(1000);                    // keep LED on for 1s
digitalWrite(13, LOW);  // turn off LED
delay(1000);                   // keep LED off for 1s
)

Tom.. :smiley: :+1: :coffee: :australia: