We have a dryer that was not tumbling. We turn on the dryer, choose the settings, and then press start. We would just hear a humming sound but the drum would not turn. We could open the door, manually rotate the drum, and then it would generally start fine. I had already replaced the drum belt, idler tensioner pulley, and the four rollers, in an attempt to address this issue. I am not certain what to test on the control board(s), but I tested the idler switch (good), the relay to the blower / motor (good), and the 5 and 4 connections to the motor (good, I think). When I tested the 4 and 5 connections, initially, I got something like 3.7 ohms, then pressed the centrifugal relay switch and got the same ohms reading. Once I released the relay switch, then the ohms went to the expected 1.7 ohms or so. Is this the reason the drum won't turn, or is this not an issue? What else can I test to know what part(s) to buy to fix this issue? Your help is greatly appreciated. Thank you, and have a blessed day!