Hi @midnight
By default fan does not start when board is cold. Fan will be turned on if board reaches 55°C and FAN will be turned off when board cools down to 45°C.
Which board version are you using? You can find it on board silkscreen, it should be something like:
LimeSDR Mini v1.2 or LimeSDR Mini v2.4.
From your previous post looks like you are not using LimeSDR Mini v2 but you have older LimeSDR Mini v1 or this is different board?
regards,
Vytautas