Welcome to the forum! The first thing to look at is whether the thermostat works well or you put it new, if it does not open when it heats, that the circuit is well purged and an important thing is that the fan works when it reaches its temperature (whether electric or viscous coupling). If I burn the board before, you have to know why I did it, if not, you risk it again. Check the sleeves, that the water pump works, and the radiator is clean, and that the heating radiator has no leaks, but above all the thermostat. Greetings!!