The thing is, even at a secondhand store, if the product has a defect that makes it completely unusable (like a DVD player that won't turn on), you can file a complaint based on the Consumer Protection Code - the "sold as is" disclaimer doesn't cover hidden defects, only normal wear and tear. The seller may have said that, but the law doesn't let them off the hook for a broken product. It's worth going back there, showing them it doesn't work, and trying to negotiate; if you can't get anywhere, you can take the case to Procon - it's free in any city - and they'll investigate whether it was really a manufacturing defect or if you damaged it after leaving the store.