Have tried what the manual says (CHANGING TEMPERATURE SCALE FROM C° TO F° OR F° TO C° The“---“willthendisplaywitheithera“F”ora“C”(FahrenheitorCelsius)for3secondsafterpressingtheOn/Offbutton. Ifyouwishtochangethescalefrom“F”to“C”orfrom“C”to“F”, presstheOn/Offbuttononceandholddownfor3seconds. Ifyouwishtochangethescale,simplywaitthe3secondsandusethermometeraccordingtothefollowing instructions. ) but I still can't change it from F to C. What am I doing wrong???