I recently acquired a Family Computer Robot (Japanese R.O.B.) and have been having a weird issue with him. He responds to commands from both Robot Gyro & Robot Block (Gyromite and Stack-up) well and moves properly, but when commanding him to move left or right, one out of every 4 or 5 times he will complete his movement, then immediately start turning in the opposite direction I commanded and will keep turning indefinitely until he goes as far as he can turn. However, the motor will keep running and he will not respond to commands at this point until I cut his power.
I checked the spring/shaft on the gear assembly on the bottom (the one that dictates his left/right movement) and the thing is completely solid. No issues there, no worn teeth, just randomly moves and gets stuck turning after given a left/right command. Usually when being told to turn right rather than left. I'm completely at a loss as to what the issue is here. Up/Down Open/Close movement has no issues whatsoever. Any ideas?