Hello I have an mp3 player plugged into my computer and I want the audio to pass right through to my speakers. This normally works fine. I don't want to have any other programs open on my computer as I am working on it at the same time. This is why I pass audio through. This is a refurbished dell precision t5500 I just bought recently. Originally it worked just fine but the next day the audio did not pass through. Once a reboot fixed the problem but that only worked once. Here is what I have tried: I went to the "sound" dialog in device manager, then to the recording tab. The line-in device is enabled and it shows green bars that pulse with the music playing from my device. I opened properties for the line-in device and confirmed that the "listen" checkbox is checked, and that the levels are high. Next I checked that I have the latest driver installed. Then I used windows sound recorder to record audio from the MP3 player and that worked. So I can use sound recorder to record music and then play it back through the speakers but the audio will not pass through. Finally I disabled and re-enabled the audio device from the device manager and rebooted. This changed nothing. The current state I can record and play back audio from the line-in device but the audio will not play directly from the speaker. All audio levels are set correctly and everything is enabled.