[Pete_D]

I've seen a similar accidental case where some internal cable in the PSU had gotten dislodged and was partially in the path of the fan blades, with the repeated contact making a chainsaw-like noise. Luckily it was discovered before the fan cut through the casing on the wire.

[chedabob]

Hah, I had a SATA cable jammed into one of my GPU fans. I cursed Sapphire for building such a poor card that failed out of the box.