You can contact our technical support at 916-377-7000. If there is a question if the processor is still under warranty they will ask for a copy of the receipt to make sure it is still under warranty. Retail boxed processors have a 3 year warranty and OEM or Tray processor only have a 1 year warranty.
I'm going to go out on a limb here and say that since they have a 3 year warranty you are probably covered since the very first Core i3 5xx processors were released in January 2010. You may want to hurry if you have an i3 530 or 540 though