I had the same problem about the second time I used my 732. Got new probes and paid attention to what the problem could be. I honestly think it was me! I noticed that where the lid shut on my 1320 and I was passing the probe wire through the door, the probe wire was getting slightly smashed. I wonder if when opening and closing the lid, I let it shut a little too hard a time or two and kinked the wire or somehow lead to the failure. Since, I used a dremel to cut a little slot and I make sure the probe wire stays in the slot..have not had another failure. Hope this helps.