Ray, Zman: thanks for your responses. The Halfer DH220 is an early MOSFET SS amp. However, having never owned a tube amp, I have to admit that I've never even heard that you must have a speaker connected to all of the terminals in order to turn on a tube amp. I can't see how not presenting a load to drive would affect a SS amp, but I suppose tubes really are a different beast.
I have a quasi-ending to this. I ended up filing with paypal and offered the seller a compromise. I would keep the amp and he would refund $50 of the $120 purchase price. Given that I was already out the $20 for shipping and I'd have to pay another $20 to send it back it seemed more cost effective to end up paying $70 and still have the amp and maybe fix it instead of going to the trouble of packing it up and sending it back to get a net $80. Essentially I figured it was a choice between being out $40 and have nothing to show for my trouble or be out $70 and I can use the Hafler to practice my "why won't this work" skillset. There ya go.
In the end the seller wrote back and accepted my offer, so now I am the proud owner of half of a Hafler DH220. The seller has been adamant that the amp was sent in working condition. He has no reason to lie at this point and I'm not going to argue--I think it is very likely the amp was damaged somehow in shipping. Now I am hoping to figure out what happened and try to fix it. This will likely be more difficult than I hoped at first since I have not found any outward signs that the amp isn't functioning save for a burnt fuse and no sound.
So that's where I am at right now. A few people have mentioned that I might have blown the fuse when I turned it on. I suppose this is possible. If the amp was damaged it is possible that the fuse blew when it was turned in. I have what is perhaps a naive question. It has been quite some time since I have blown a fuse--in fact I've only ever done it once and that was almost 15 years ago--but doesn't a fuse blowing make a little sound? Or am I just off my rocker? (the answer to that question is probably yes, but you know what I mean). I ask because I never heard any sort of noise. The channel was always dead silent, I never heard what I would have thought was that sound of a fuse dying, and even the cooling fins on the right side don't heat up (on the left they get toasty).
As usual, any feedback is appreciated.
Thanks, Aaron