Canaan warrants the purchased product(s) to be free of all defects in material, performance and workmanship for 360 days for products from the date of the delivery. This warranty extends to the original buyer (and each successive buyer within the warranty period). Within the period of this warranty, Canaan will repair or replace, free of charge, any part proven defective in material, performance or workmanship, but mining earnings will not be compensated. You can work with Canaan after sales engineers online to find out the faulty parts, then we can send you the replacement parts directly via the express companies. In this condition, Canaanwill pay the shipping cost of the replacement units shipment.