I tried to sell some stuff here a few times, unfortunately without much luck. You can try craigslist, echinacities and other websites (sorry dont know any sites for shenyang). The only time I got lucky selling something was by selling it to some foreign friends or my gf chinese friends. Apart from that, no luck, even with taobao, baixingwang and all the other chinese websites (i put it on chinese, or lets say my gf put it there in chinese^^)

once i also wanted to sell an old phone of mine, i finally sold it at a phone mall where some stalls also buy old used phones. price was rock bottom low, so dont expect a price you can get on ebay or with a friend, but at least you can sell it, thats for sure...