Hi,
Pin 1 one H bridge is the enable pin, or like the H bridge switch, when it gets voltage it starts running.So if you can measure voltage coming out from pin 9 of arduino 1st stage is checked. After what H bridge will do is compare voltage in pin 2 and 7 (they cant be both HIGH or LOW at same time). if pin 2 as voltage and 7 doesnt it will spin in one direction; if 2 doesnt have voltage and 7 does have it will spin in the other direction; if both pins have voltage or if both pins dont have voltage it will not spin at all. So this is your next step,check the voltage on both pins...