Hi, Emanuel Berg photographed: > https://dataswamp.org/~incal/ebchw/fan-top.jpg
The case fans look like they would produce a lot of wind if really running at full speed. Whatever, i'd make a closer photo, unplug them, listen how much noise is missing, and then plug them in again guided by the photo. That perforated metal plate at the bottom looks suspicious. Power supply and hard disk cage, if i remember correctly ? How is the noise if you unplug the power of the whole mainboard ? Have a nice day :) Thomas