Your oven has a thermocouple at the pilot assembly, which, when heated, acts as a flame proofer. It sends an electrical signal to the gas valve, telling it to open. Over time the part wears out and the signal gets weaker. Yours is the same type that's used in water heaters, so you can find a replacement at most hardware stores. The sensing bulb slides out of the pilot bracket, and it has a jam nut where it attaches to the gas valve.
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The thermocouple has already been changed (last summer) I believe something else may have gone wrong...Do you have a solution....Thanks again