s12original

Does anyone know how to find the value of a burnt resistor ? This resistor is from an industrial inverter , which means that there is no schematic or any other information , besides the "send it to us to fix it" . It is totaly discolored and changed into ........... black . I can measure resistance (16.5M) but i can not trust that measurement because it has probably increased the original value due to severe heating . Any information will be appreciated