Pictures below shows picture of a new 269 that we opened . The motor was opened less than an hour and was never put into much stress. Yes , this motor is recently bought. It looks as though it was a manufacturing defect. There was no debris found in the motor .From the wires , you can see that the motor was just open.
As for the motor controller 29 , when my team found out that the robot was not working normally after a practice , we checked and it appears as though the motor controller 29 is burnt out .
Comparing the broken internal gears and a normal one
Unfortunately , we are the only teams facing this problem.