Dell Inspiron 17 5000 series, Windows 8.1, works great with speaker audio, plug in a headset or headphones (tried multiple sets), and I get sound, but I get a squealing sound. Not feedback, the mic is muted and I'm familiar with what that sounds like. If I plug in a USB audio adapter, works great. It also doesn't give me any trouble if I'm rebooting up until the time I get into windows. I've deleted the device and reinstalled in device manager, tried disconnecting all power sources and other devices (in case of some sort of ground loop)... at my wits end. Any ideas?