I have a consistent error code SY EF on a Frigidaire gallery series refridgerator Model: LGHB2869TF7 Serial: 4A94006157 French door fridge. Which based off what I know is a communication error between the board and the fan. Upon further review found that my evap fan constantly runs on only hi during this error stage. I’ve actually already had a technician out and based off what his guy at Frigidaire told him it had to be a bad board. He replaced board didn’t change anything. It could be the fan I guess but it functions outside of the error stat fine which makes me think the fan isn’t the real issue. Also when you power the whole unit “off” while it's in the error state the fan continues to run on high so idk? Recently I have figured out that once I put it in manual defrost mode the fan is able to shut off and resume normal functioning. It usually brings the error back in about 48 hrs. No ice accumulation anywhere on the inside to point towards defrost issues. Defrost thermostats isn’t bulging and both the thermistors in the freezer and fridge seem to be readying correctly? Durring the last episode it seemed as if the fan was "pulsing." Would this be caused by a bad fan or something else all together?