was given a gently used kenmore model 66575775890 free standing oven, in excellent condition, by a family member. after transporting it home, then converting it to run LP, the stove top works great but both the broiler and bake burners don't work. the igniters do work, they both glow VERY bright and hot. there is no sound of gas coming out nor is there any gas smell. i checked the gas safety valve and it shows just under 3 ohms resistance (normal). any ideas?