These products requires six  "AA" size alkaline batteries for operation.  These batteries are not included.  Make sure that all six batteries are installed by removing the battery pack and filling both sides with three batteries on each side of the pack.  If replacing batteries, make sure all six batteries are replaced at the same time.  Only partially replacing the batteries could also cause a no power situation.  These  products should NEVER be powered by a 12 volt source.  Doing so will damage your unit and it will need to be returned for service.  This would not be covered under warranty.