AM SERVICEING A FRIGIDAIRE RANGE M#PLEFM399DCB. IVE ALREADY REPLACED THE CLOCK ASSEMBLY AND THE POWER SUPPLY/RELAY BOARDS. I GET ERROR CODES F7,F20,F22.THE PREVIOUS SEVICEMAN BEFORE THAT CAME OUT TO FIX ANOTHER PROBLEM WHILE UNIT WAS STILL UNDER WARRANTY TOOK THE TECH SHEET WITH HIM AND FRIGIDAIRE SAID THEY CANT SUPPLY ANOTHER. THE PROBLEM SEEMS TO BE INTERMITTANT. THE LONGEST TIME THE UNIT WENT WITHOUT BEEPING WAS APPROX 48 HRS AT THANKSGIVING. IS IT POSSIBLE THAT IVE GOT A OVEN TEMP PROBE WITH AN INTERMITTANT PROBLEM? IVE BEEN SERVICEING APPLIANCES FOR ALMOST 30 YEARS, BUT IM REALY PULLING MY HAIR OUT ON THIS ONE.