Time/clock on stove top begins to beep and display an "F1" signal. Since we don't have a manual, we aren't sure of what the problem is. We have unplugged the stove for hours at a time to deprogram, but after we plug it in, the beep returns, even though the beeping may take several hours to resume. What can we do to stop the "F1" beeping signal and get the stove clock and control system back to normal? Any idea of what causes this problem? Stove is several years old and was in the house when we bought it four years ago; unfortunately, no manual was left with it. We're not even sure of model number as the only data on the stove is the serial number which I have given above as a model number. Help! Thanks, Frank Canino