1. Make sure your screws are not too tight, otherwise the servos won’t be able to move

2. Make sure you are supplying enough power to the HERO Board. Use USB 3.0 and not 2.o, or add a 9v battery supply in the barrel jack.

3. Make sure that the servos are able to perform their entire 180 degree range of motion, and if not, you might need to re calibrate in the code provided on the product page.