More than likely this is the actuator inside the door. If only one is doing this and it will not move either way then you will need to take the door panel off and at least see what is happening.
I included the instructions on how to replace the actuator. It includes the procedure to remove the door. If it were me and I were going to go this far, I would just replace the actuator even if you can get to start operating again. Removing the door is not something I would want to do twice just in case it stops working again.
Let me know if you need more information. Thanks
Images (Click to enlarge)
Sunday, July 14th, 2019 AT 5:38 PM