Electrical outlets are "Daisy chained". In other words when one stops work, those beyond it stop.working too. Usually it's a loose wire, bad outlets, or bad ground. Buy a $5 plug in tester at Home Depot. Start with the GFI WORKING DOWN THE LINE. Don't forget the outside outlet(s). If it's a bad outlet, replace with household type. Use screws to tighten wire rather than push in. Hope this helps.