The manufacturer warranty that Sharp offers as of 2015 is 1 year, and covers parts and labor, including in-home service. The magnetron tube is covered for an additional 4 to 6 years, depending on the microwave model.
Any parts found to be defective in the first year would be replaced for free by an in-home technician provided by Sharp. Accidental damage is not covered under the manufacturer warranty. Sharpusa.com has a support section where customers can enter a warranty claim or find information about replacement parts and retailers. Sharp contacts claimants to diagnose the problem and file a warranty claim.