If the fan has a sleeve bearing and it has positioned at inclined angles for long periods of time, 1000+ hours of usage in this manner, the internal rotor will warp due to un even and insufficient lubrication as well as a buildup of carbon byproduct and the motor will eventually seize without much warning. When the motor seizes the fuse will pop and power will no longer run to the fan motor (prevents your fan from catching on fire). You will need a new motor and a new fuse, but the fan speed capacitor should be fine.