Recently I've been noticing performance drops in my macbook as it gets hot. These drops have been largely whilst watching youtube videos in 720p, or when gaming on my bootcamp partition. I initially put this down to my hard drive filling up and general use, until I noticed these drops in performance disappearing when the fan started up. I then downloaded smcFanControl in order to work out what was going on, and discovered that my fan remains at 000rpm regardless of temperature. No noise is emitted from the fan either. On the mac partition the fan rarely starts, occasionally crashing from overheating before it has a chance. On my windows partitions, it does start when temperatures reach very high levels, increasing performance, but stop when the system cools down a small amount, causing the performance to drop again. On average this leads to a fluctuation between 60 and 4 frames per second on Starcraft 2 (60 with the fan on of course). I assume it working on windows is due to there being no system in place to prevent heat damage, meaning the current temperature threshold is above the mac's cut off point. I attempted to resolve this by manually increasing the rpm on smcfancontrol (which did nothing) and cleaning out the fan. Eventually, I decided to remove my macbook's lower case and view the fan while the laptop was running. I discovered that on several occasions the fan rotated once and then stopped, moving incredibly slowly. Could this mean the fan is jammed by something? Or is it likely to be a software failure? I have already attempted a PRAM reset which did nothing, so I assume its a hardware failure. Is it simply blocked or do I need to invest in a new fan? Any help would be extremely appreciated!