I just got it through my door earlier today.... man that monster is huge and heavy! Nearly broke my back lugging it up the stairs, and my back is already broken. It's in mint condition... not a scuff or scratch on it!
But anyway, the headphones symbol is engaged. I tried doing a reset, but no go there. I guess I'll have to see how much it'll cost to get it fixed. The previous owner lost the receipt, and he got it from Circuit City before they went under.
Congrats!

Tell me about it (weight), my back was sore for a week, after carrying it by myself, walking for about 8 city blocks, plus 1/4 mile, before finally getting it home. Total distance: approximatively 1 full mile.

Try this & see if you can make it.
--> But remember too, I planted trees for just over 30 years, carrying loads of trees from my set of quad-bag, with up to 75 pounds a load, up to 10 or more loads a day, in steep rough slashy terrain, at up to 80 degree angle slope.

And I ain't kidding you either.
* About the headphones jack issue: I wish that I can help you, but I sure hope that you can get it fix. I'm certain that it could be fix.
Do ALL you have to do, just to keep this beauty in reach of your ears and soul.
Call Onkyo, visit your nearest audio repair shop, even call the Pope if you have to.
Bravo!
Bob