I Have a hovabator 1602N with an egg turner. I have gone trhough 3 batches of eggs, and have gotten no chicks! in each batch, atleast 3-4 of the eggs would make it to the last 3 days but then they would never hatch? I really dont want to buy another incubator because i dont want to spend more money. But should i buy a special thermometer to make sure the temp is set right? What about a fan? Would that help? Please help! Thanks!