It's likely the thermocouples. Each burner has one, and over time the electrical
"ground" connection at the burner gets corroded. My Force 10 stove had this issue, and the fix involved adding a star-washer to the thermocouple mount. Your oven
might have a different mechanical arrangement.
It does seem unusual that *both* burners show the same problem, but I suppose they could both be corroded. Perhaps there's some different single
point of failure, but I don't know of one. However, I'm no expert.