cooling fan not working?

Hello - we have a smeg range style electric cooker. 2 ovens, grill and 5 gas hobs. Yesterday the electrics tripped while the oven was on (with quite a load bang!!) and when we put the electrics back on both ovens were still working, and their fans but when you turned them off the cooling fan was not coming on. This was the case for the small oven but we are a bit reluctant to test the big oven without some advice. Can you help?