When I buy a box from a vendor I expect it to have been tested and for it to work. When it doesn't work, I don't expect the vendor to deny culpability. Then when they realize it really is something on their end I definitely don't expect that I should have to do more than half of the investigation to find the problem. I mean it seems obvious. You make a product, you sell that product, you are responsible for getting that product to work. And when it doesn't, you are responsible for troubleshooting. Sometimes I feel like I pay for parts and labor and get parts and laziness instead.