Do you have an oven thermometer in there? Is the fan actually keeping the oven from being at the temp you want?
I don't have an oven thermometer but the oven was warm not hot and was not cooking. Could be a broken thermometer in the stove thus causing it to function wrong.
Get an oven thermometer, for two reasons (actually three if you count the fact that oven thermometers are cheap as dirt).
One, no stove on earth, or at least no reasonably affordable stove, is actually accurate--you can set it at 350 all you want but it's not actually at 350, and the 5-10 degrees it's off will affect your cooking (especially baking). The top will look perfect when the inside's still not cooked, or vice versa, so either the top or the inside will always be not quite right. An oven thermometer will tell you about how much your stove is off by, so that you can adjust.
Two, once you put a thermometer in there and find out (this is what I'm anticipating you'll find out) that the temperature is constant and is within 5-10 degrees of what you set it at, that will tell you the fan is working just fine--it's in part because of the fan that the temperature is constant (i.e. same over time) and consistent (i.e. same in different parts of the oven). If, on the other hand, the thermometer doesn't tell you that, then you'll know either the oven thermostat and/or the fan needs attention.