Arduino with NEMA34 Stepper and Diriver

Other Hardware Motors, Mechanics, Power and CNC
3

It's because you are trying to go from zero speed to 5000 steps per second (1500 RPM) instantly.
Try a sane speed of 100 RPM and 3000 micros per step. How about the enable pin?

void loop(){
  digitalWrite(stepPin,HIGH);
  delayMicroseconds(1500);
  digitalWrite(stepPin,LOW);
  delayMicroseconds(1500);
}