Microwave Turntable Doesn't Turn

I was a very baisc form of bad luck this mornign as my banaitsa when into the mocrowave to warm them up. After a 1 minute bust at full blast I took them out to find that the middle of the banitsa was piping hot and both ends were cold. I didnt' understand why until I put my cup of water fro the coffee in the microwave. The turntable didn't turn, it had broken down. Looks like another microwave we have to purchase. The guarantee was for one year, we have had this one for only 18 months!