What does it mean if there’s a slow blinking red light when I close the lid? June 22, 2022 19:01 Updated This means the Engine batteries are low. Replace with two new AA alkaline batteries and try again. Related articles Do I need a prescription to use the Men’s Rapid Fertility Test? What does it mean if there’s a single red light flash when I close the lid? Will OnDemand test results for a minor dependent automatically be loaded into an existing linked Labcorp Patient account? Has the Men’s Rapid Fertility Test been evaluated by the U.S. Food and Drug Administration (FDA)? How long does this test take?