I will again share the fan control modification tutorial for IC706 - first version. Open the bottom cover at the connector for connecting the fan (PA-Unit) is towards the back TRX R63-47ohm large SMD. Carefully remove it with a micro soldering iron and replace it with a value of 100ohm, (constant fan operation). This R63, which you have left to install in place of the original resistance R41-22ohm. (increased revolutions at TX). This modification will make TRX operation more pleasant for you. The modification is already used and functional in practice.
73! OM5AMJ