Hello, After having my iMac 2017 27" for 2 weeks already, it just started making some subtle rattling noise. At first it switched from being silent (only hearing the fan at 1200rpm) to the additional rattling sound (also with the fan at 1200rpm). Now I've this subtle rattling sound permanently in the background. This is something you only hear if your room is completely silent but I'm afraid it may get worse over time. Anybody else experienced this and knows where this is coming from? I assume it is a problem with the fan itself that it doesn't run as it should. Is there an app that allows me to control fan speed? would love to pause it for a moment.