My in-laws have bought a 50 Series Atara S and I actually prefer the gearbox in that as opposed to our 40 Series Aurion, it just seems much more poised and responsive. Hopefully the 50 series Aurion has lost that docile acting transmission.
They will only come on once it reaches a certain operating temperature. There will be a fuse, check all fuses. You then need to determine whether it is the fans or the switch/wiring.