All the complete products have two years warranty from the delivery date. If the product has issues or you are not sure about its features, please mail us first instead asking on various internet places. The chance that a third party to be able to support an issue and answer to a question better than we can is minimal. Moreover, unqualified support will increase the chance of doing something wrong or even damage, and we do not encourage to ask for support as it can lead to loss of warranty if the products were damaged following wrong advices given by unauthorized persons. We are convinced that we know more about our own products than someone else, and we pursuit to ask us first. In case of malfunction, the product must be sent back, we will evaluate the condition and the cause of damage, and we will repair or exchange, depending on the condition. If the product was damaged by itself, DOA or due shipping, and not because negligence, intentionally or improper usage, it will be no charge for repair or replace, just for shipping back. The shipping cost back and forth will be supported by the customer. If the product need to be repaired after the warranty period, we can repair without charging the labour cost, just the price of the parts, and the shipping back after is repaired. We can provide assistance for diagnosing a malfunction product or identify if the product is really damaged or just connected incorrectly, but we cannot repair the product remotely by phone or email due to the complexity of the circuits, lack of tools and parts on the customers side and definitely the risk involved with high voltages present on the boards. For complete and professional repair, test or replace service the product MUST be sent back. We do NOT issue refund after the warranty period from the purchasing date expires, or for a product which was intentional damaged or due to miss-usage, or due to unauthorized modifications which lead to failure.