Electric blanket stays flashing FF. I turned the blanket on and it flashes FF. I unplugged it for

Question

I turned the blanket on and it flashes FF. I unplugged it for half an hour and then plugged it in and turned it on again with the same results. It will not let me set the temp. I want.Sunbeam 33600RN 17280PN 107882-003Style 84 SK