I have heard of this happening before. Sometimes it is just a component in the 4-in-1 that goes out. Other times it could be the battery that causes the problem. But since you called Horizon and they want to replace it for you, that is a good thing. I have been using mine for over 6 months and haven't had a problem with mine at all. Others have mentioned the same problem you have mentioned. Remember, these are electronics and sometimes they just go out.

Gook luck and hope you get into the air quickly.