APPLE IPHONE 3GS 16GB - STUCK ON APPLE LOGO +

FOR SALE IS MY APPLE IPHONE 3GS 16GB PHONE WORKED WELL UNTIL ONE DAY TURNED IT ON AND GOT STUCK ON THE APPLE LOGO IM NOT SURE WHAT THE PROBLEM IS AND DO NOT HAVE THE KNOWLEDGE TO FIX MOST LIKELY AN EASY FIX FOR SOMEONE WITH THE KNOWLEDGE