My did the e-zack same thing and its dead talk to castel they told me to send it back. It was a good speed control before, & I had ran it on 6 cell lipo for 3 months then I tryed to update it now its fryed. so my advice is dont try it .send it to castel and let them update it. they say they are having trouble with other speedos doing this same thing. also i tryed 3 other cables & links still nothing.