I bought this unit second-hand from you. Now I can't register the device on the Atomos site because it has already been registered. For this reason, I cannot activate certain elements. What can I do about this?

You mean dB, i.e. volume? I can't measure that. But at the beginning, the fan goes to maximum and adjusts to the necessary value after 4-10 seconds. Unfortunately, that's the way it is. This gives the impression that the thing only howls when it starts up. As a wildlife filmmaker, that doesn't make me happy either. Otherwise, I am very satisfied with the device.