Definitely open a case with ebay if that's what it comes to. I've done it a couple of times and have received a full refund, either from the seller, or if the seller wouldn't cooperate, ebay reimbursed me and I presume got their money from the seller one way or another.
You do have to contact the seller first, but if they fail to respond or accept responsibility, that's when you escalate with ebay.
I've done both. Most recently, I contacted a seller and advised that an item he claimed was working was in fact non-working and he didn't even reply -- instead he immediately processed a refund via PayPal. He had a no-returns policy and he really meant it. He didn't even ask me to send the item back.
I have my dad's Sawyer's 500R from the mid-'60s and a sh*tload of slides to go through. I shopped for spare lamps and couldn't believe the prices, so the viewing process has been on hold. I recently found the same projector destined for the e-waste pile and extracted the lamp from it, which appears to be good. I don't want to get everything set up only to have the lamp burn out on me and no spare handy.