Frigidaire air damper - loud buzzing, replaced motor no change

Refrigerator & Freezer Repair
1

I have a Frigidiare side by side, only about 22 months old, all electronic controls.

Came home one day to hear a loud buzzing/ratcheting noise from the fridge. Got the parts diagram and determined it was the damper control servo motor making the noise.

So I ordered a new damper assembly. Annoyingly the one I got didn’t have quite the same setup with respect to switches or door design, but the motor was the same. Swapped in the new servo motor and the new one is doing exactly the same thing.

Ideas?? The damper appears to have two settings, there are two rocker switches that I guess provide feedback to the control board as to whether the door is half open, full open, or closed.

Not sure where to look next. Control board? The switches themselves?? Motor still "works" but when it is in the open or half open state it makes this constant loud buzz which is driving me nuts!!!

2

…which strikes me as bizarre, since it’s a 120vac motor with 2 wires running to it. I can’t imagine what could be going on to send the motor into the buzzing fits that it goes through.

The model of the fridge is PLHS68EESB6

3

Hmm, ok I’m still at a loss, the circuit looks pretty simple… but what’s controlling the power to the 2 toggle switches? Would it be possible that it’s one of the toggle switches with the problem? That seems unlikely as the "pulsing/buzzing" is so consistant…