I have a Samsung SMH 1713S built in microwave Originally I heard a noise inside of the microwave and thought that it could be the turntable. I made sure that it was clean and positioned correctly. That did not resolve the noise. So I removed the front panel to replace the charcoal filter. I noticed in the back of the unit that there is a white squirrel cage and that I can rotate it. What I am wondering is what does that do and is it supposed to move when the microwave it on and working?
The squirrel cage fan is for the exhaust feature on the OTR microwave unite. It only runs when the exhaust is enabled.