I have a desktop where the sound output has become erratic. I bought one of these $2 USB devices to bypass it. I leave it unplugged most of the time
http://www.ebay.com/itm/USB-2-0-to-3D-AUDIO-SOUND-CARD-ADAPTER-VIRTUAL-5-1-ch-High-Quality-New-EN24H-/120987665271?pt=US_Sound_Card_External&hash=item1c2b6d4377
Choose "price and shipping lowest first" in the sort box. Hong Kong business.