Time Capsule makes weird Fan noise

Hey guys,

I got this Time Capsule and since a week it’s making weird noises during normal operation. It’s not the HDD because when I access it via my Computer it turns on and up normally. Also accessing and storing data works normally. So I assume that it’s someway the fan that’s either blocked or broken. The sound is like something is starting to turn and then it suddenly stops. I saw the tear down for the HDD but now for other modules.