Dear customer,
We do not guarantee but warranty on our products.
For details, see [...]
The warranty only beginning defects are repaired free of charge, to all these defects are counted, which occur within the first six months. Then the burden shifts to the buyer (§476BGB).
Within the remaining warranty period we will continue to repair all defects, as we do but give you the material costs into account, but not the performance.
Only if you provide an opinion that it is in spite of the late occurrence of the error to a defect caused by us at the beginning, we would repair the defect free of charge.