IPC427D temperature sensor chip

I have just installed our Linux distribution (Slackware 14 derived) on a IPC427D pc box. All is running well but I cannot detect the temperature sensor chip. Using the sensors-detect utility included in the lm-sensors package, only the intel chipset core sensors are detected (supported by the coretemp kernel module). No other externel sensor chip is detected.

Is there any temperature sensor chip installed on this box ?

Trying on an older PC677C, sensors-detect finds a chip supported by the lm90 kernel module, and all works fine.

Thank you for any help.