...So I take it I can't say 'it works now, but I can't guarantee that it will work when it gets to your house'? I mean, how else can you explain that 50 year old cameras sometimes stop working after long transglobal shipping? I wish I knew the right words to use to explain. Seems like it's a trap for the seller no matter what. If I don't say it works, people ask "does it work?" If I say it works, now it has to work no matter what?...
Well, the seller shouldn't be able to screw the buyer either, right? So if a seller has an item that he knows doesn't work, and in the listing says: "Works perfectly!", and then when the buyer gets it and it doesn't work, all the seller has to do is say: "Well, it worked fine when I shipped it.", and that's it? Go pound sand?
If the seller says it works, and the buyer paid for one that works, then the buyer has a right to one that works. If it was damaged in transit, then it's an insurance claim situation. If there's no obvious shipping damage at all, then what will probably happen is that the buyer will return it for a refund, which is the only fair resolution.
...And how long of a window does he have? The sale took place on November 11th, it's been six weeks, all in all.
You have 45 days from the day the listing ended. As of midnight tomorrow he's done.