请教，房间里的风扇不转了，motor(马达)好像在努力在转，但叶片不转

房客来邮件了，说是房间里的风扇不转了，房客说motor在转，但叶片不转。大家碰到过这种情况吗？什么原因？

这是房客的邮件：

“it sounds like the motor is trying to turn but nothing is happening. I think there is a shorage in it, the light works fine though so hopefully its a easy fix”