I have a Athearn Genesis P42 unit that I bought a few months ago and just started running it… I notice a weird humming/whining noise (sound compares to a belt slipping noise when the AC belt is loose on a car when the AC is turned on) when it is running above 35+ on the 128 speed scale on a DCC system. I have not run it much and don’t know if the gears are not lubed well or what.
I have two of the units and have never noticed a noise that you are describing. I have run mine quite a bit. It sounds like a bearing in the motor could be dry. A tiny bit of light oil might fix it if you can figure out where the noise is coming from.
Good luck.
Thanks. I also read something similar on another forum on the net about dry motor bearings. Will give that a try.