OGNasty is a reputable escrow around here.  If he's not interested in validating the hardware itself I'd be willing to do it for you for $50(payable in BTC at the time that I ship it to the new owner).  For that I'll unpack it, inspect it for physical damage, power it on and point it to litecoinpool.org using your worker info so you can see it hashing for a few hours(I've owned several of these miners in the past and am familiar with configuration), and then repack and forward it along using a shipping label that you provide.  I'm located in TX.  I'll escrow the miner funds themselves as well if you like.

If it came from Zoomhash it's likely just fine assuming nothing got damaged during shipping, they're a trustworthy team.