Last night we had a power failure that lasted about 2-3 hours or
so. (The refrig was not opened during the failure). Our 2004
Whirlpool/Kenmore Energy Star 21.6 cu ft refrigerator started
making a strange noise after the power was restored. The source
of the noise was the fan in the freezer compartment (evaporator
fan). By applying pressure to the plastic guard in front of the
fan, the noise could be worsened or made better. I would try to
stop the noise, only to have it return later. By this morning
the noise was gone completely, and even trying to move the guard
doesn't cause it to come back.

The noise sounded as if the fan blades were striking something.
I don't think they were striking the plastic fan guard. Is it
possible that some frost build up during the power failure caused
this? Is there any risk of damage that could have occurred to
the refrigerator? It seems be working perfectly at the
moment. (2 more months of warranty coverage).

Thanks!