I have the same issue. NO sound at all on my Insprion 6400. The sound would go out intermittently and for the longest time. I would shake it a bit and it woudl come back. then that didnt work so much I would have to REALLY shake it to get it to work. Then after a bit only shaking it a certain direction would work. That turned into putting something in the USB port next to the audio jack and when I did that I would get sound from the speakers. Then that stopped working. And I started to put the microphone plug in and out of the microphone slot and that worked. That quickly turned into having to wiggle the microphone plug. Then later angle the microphone plug. And now nothing. I saw a video on resoldering it . What a PITA. 2 hours of my time to fix or try the usb audio device. this one seems to be done for me. My Dells have been buggy for me since 1997 on to HP.