Gas has stopped working on my oven?

I have an older model (maybe 20 yrs) Diplomat Softline gas oven with separate grill above. The digital display has suddenly stopped illuminating and the gas has shut off. I can hear and see the ignition firing but no flame in either oven or grill. Also the RCB on the fuse board is fine. The serial number is 00726107 and model number 200504035. The kidz were using it over the weekend and when I got back it had stopped working. Many thanx for your help!