Fixed the error on my i7
Is the motor working too hard to turn the fan blade?
I opened up everything to get to the dowel of the fan blade.
I tried turning it by hand a bit firm when I did.
The dowel which has approximately 3 washers (two are together) on it.
After removing all of them, I put 1 drop of oil and graphite powdere onthe dowl where each one of the washers isand where they touch each other or the housing. (especailly important is where the dowel attaches to the plastic housing)
After this I put it all back together and turned it again by hand which moved more freely than before.
It has been working GREAT ever since.
Hope this helps