Thank you Jarno and Jasem,

With your input I found the "control" tab in the driver panel, with the relevant slider FanSpeedAdjust. Which was at zero. I set it at another value and everything works perfectly.

This new possibility of the SDK is indeed a great thing, since, as you may now (several threads on CloudyNights on this), the fan may yield elongated stars at long focal. Because the thermal signal is low on IM571, it is not really necessary to go below -10°C, which can be easily obtained with a fan at low power, or even turned off, in winter time (temperature already at 0°C or below).

Philippe

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