I bought a cheap three rgb fan set for 20 dollars on a reseller website. I have had them for a good two months and recently picked up the fan speed to compensate for the high hard drive temps. Since then my middle case fan has been making this Rattling noise and when i stop it with my finger the noise ceases. This just started two days ago. When i stop the fan with my finger the noise goes away and the fan picks back up to its increased speed then the noise comes back. Its quite loud and im surprised a case fan can be quite audible.