You have to bye two new front motors I had same problem with a alias quad copter bought 4 new motors because 1 stopped working and then another and so on and so forth, put new motors in and was good to go make sure you replace motors one at a time to make sure your drone will fly again once you put it back together, I took all four at waiting on my motors and then had to figure out how each blade turns and pushs air down in my case it was two counterclockwise and two clock wise.