Norcold 682 refer lights on LP but does no stay lit

In the past when this problem occurred it was rust flakes falling on the burner. Then the burner slots rusted out changing the air to LP ratio causing the same problem. I replaced the burner tube and thermocouple 2 years ago and it lit on the first try until last week. I removed the tube and it was clean As well as the oriface. Removed thermocouple and cleaned tip and readjusted tip to 1/8 in from burner tube. The control board is a Dinosaur board and was replaced about 10 years ago. I tried my old thermocouple and it reacted the same as the new one. It will continue to spark with a nice blue flame then it will go out after about 5-10 secs. Both thermocouples measure continuity from tip to spade connector. Does this mean a new control board? Or is there some thing else that I could check first? Is there anything in the power board that would cause this issue?