If the defect arises more than 1 year after purchase or delivery you will have to prove that the item did not meet requirements, usually by getting an independent expert to perform a technical examination of the product and give their expert opinion at your own expense. The warranty period is suspended during the execution of the Expert Assessment
If you prove liability of the trader for the defective goods by the use of the Expert Assessment, you have the right to claim the goods again. Trader should reimburs all costs associated with the Expert Assessment within 14 days from the exercised complaint, as well as all costs reasonably incurred. Reapplied complaint cannot be rejected.