I had the same issue. Light blinking 3 times, motor won’t turn. I took it apart, cleaned all the boards with contact cleaner and tooth brush. Cleaned the battery contacts as well. Tried the trigger with a battery, still flashes 3 times took off battery, separated the motor from the drive, it wasn’t hard, there was this thing that looked like a drill bit that came out of the drive with the motor. I think it’s what makes the impact do its thing. Then I took the fan end and pulled the motor out of its housing. It’s held in there by magnets/armature. Anyways I took a scotchbrite pad and started cleaning the outside of the motor, I thought well if I’m gonna clean everything I may as well do this too. When I put it back in its housing I pulled the trigger a bit and the motor made the tone it makes when you pull the trigger a bit and you get the little led light. I figured that was the problem and put er all back together and it works now. The only thing I had a hard time with was there was this spring that gave some resistance to the forward reverse switch, I had to put some grease to hold it in place so it would stay put while I was putting it back together. You may want to find some dielectric grease for that. Anyways hope this helps.
