The only things I can think of or know of after you've checked out what the posts above state.....
I don't know exact wording so...I'm going to give it a try!!!
A couple of things may cause this....The motor shaft/s are out of "adjustment". I've also assembled a gimbal wrong! Sounds funny but it is possible! I know! My camera was upside down.
A broken sensor board. ( I don't know it's actual name. The little circuit boards on the end of the shafts.) Sometimes the break or crack in a crash.
Make sure your ribon cable is seated and the little locking tabs pushed down. The one is a little harder to get to and I've missed it before.
There are a couple of good Youtube video's that got me straightened out. I'm sure there are other reasons this would happen, but for me it's always been out of adjustment. And yes, they will get warm or hot when out of "adjustment" or put together wrong.Even if the video's are for an Adv. or a Pro. From what I've seen the mechanical part of the gimbals are all about the same as far as mechanical adjustmens on all of the Phantom 3's.
Look up "dancing gimbal" "phantom 3 gimbal rebuild" or something similar on youtube There are a couple of good video's. I'm sorry i can't remember the exact names, I'll try to find one and link it here.
There are other video's and like mentioned in the post above, the "box" part may be on the shaft 180 off. check around at the other video's and check the alignment or "adjustment". GL