I have to agree with bro storm.
For example. I worked in electronic Store. We always check the unit properly for customer and once they left the shop there is no 1-1 exchange policy, the policy expires actually when u walked out of the shop [The policy only expires with our shop and not with the brand, we still help customer to send the goods to SVC for inspection if any damage caused by the consumer came up] . When u go out from the shop, many things can happen. U can drop the thing, there can even LCI activated that we cannot even check in the shop and only SVC can check it. Thus, directing customers to the SVC is obviously a better choice as we already ask customer to check properly during the purchase. Don't just think as a customer, think what the problem the seller have to face. Just my 2 cent working in electronic shop.