However, in practice most good retailers do not make a big deal out of the burden of proof as long as there is no visible damage that could cause the issues. I

However, in practice most good retailers do not make a big deal out of the burden of proof as long as there is no visible damage that could cause the issues. I have used warranty frequently after 6 months and never had to prove it is a manufacturing defect. Of course, if you buy at some shady webstore or known-bad retailer, you might have more issues.