I know there have been threads on coil whine, but does anyone have a Mac mini 2018 that does not "hiss" when writing or reading large amounts of data or on boot up. Mine hisses, to the point I can hear about 4 feet away (very subtle). Debating if it is a "defect" worthy of dealing with Adorama returns or if it is expected behavior to learn to tune out.
Hearing a hiss at 4 feet is
not normal. Hearing a hiss at 1 foot is not normal.
So, there's three main possibilities moving forward...
1. You have an interference issue and you need to track down what's causing it, because exchanging for a new unit will have the same issue.
The way to troubleshoot is to isolate as many variables as possible. It could be
any device hooked up to the mini with a cable or even wirelessly (the display, speakers, mouse, keyboard, etc). It could be another device in the vicinity not directly related to the mini (tv, smart speaker, stereo, etc.). It could be its placement in the room. And so on.
The first thing I would try is plugging it in in a different room (even better, in a different building) without
anything plugged in, turn it on, and go from there, adding back in one device at a time.
2. You determine you have a defective unit - exchange it. Simple as that.
3. You may determine that it's easier to get a different computer than to fix the environmental/device issues.
Best of luck!