The unit is a Toastmaster, Model TUV48S , and the problem is that I do not see the fan running. Is the fan supposed to run all the time? I am assuming it is. What might be wrong, of course fan itself may be bad, does the fan run off straight 110 volts, or is it run off of a power supply that is less than 110 volt. Anyone else have this problem? Oven DOES still heat up. Main thing is Is the fan supposed to run all the time? Thanks, Tony