I have no idea what I'm doing wrong, but my servo won't move with less than 12V at 300mA from a wall wart. I've tried all sorts of sketches, including this one, but no changes to the variables make the servo stop or slow down. What's going on???

I have the power connected to the power rail of my breadboard, ground from arduino to the ground on the power rail, and the servo connected to the power rail with the white pin in arduino pin 9.

include

Servo myservo;

void setup() { Serial.begin(9600);

myservo.attach(9);
}

void loop() {

Serial.println("1500     ");  

myservo.writeMicroseconds(1500); delay(5000);

  Serial.println("4500     ");  

myservo.writeMicroseconds(4500); delay(5000);

  Serial.println("7000     ");  

myservo.writeMicroseconds(7000); delay(5000); }