I updated my profile with my system but it's a dell studio (refurb) with amd 1035 6 core processor. It's running windows 7 64 bit SP1. I have a realtek onboard sound card and an MAudio add on card. System has been working great for over a year now until just the other day. I was adding my 36 inch Sony tube tv as another monitor. I connected my pc and Sony via an HDMI-SVideo convertor box. I connected an HDMI cable to the back of the pc...then to the convertor box and then connected the SVideo to the tv. With some rigging it all works ok. It all looked and sounded ok. My MAudio has two heavy duty RCA cables connected to the card and running into the back of a Sony receiver. It was working fine/playing through the receiver then suddenly quit. No reason...no burning smell or pop...nothing. It just stopped working. I then plugged my headphones into my jack and the onboard Realtek sound card was still working. I kept troubleshooting the MAudio with no luck. I reset the card...checked the interrupts ...went into device manager and it reported everything was working. Last night, I had my headphones on and they suddenly quit. Now my onboard realtek card has stopped. I removed the MAudio card and rebooted...nothing. when i go into the device manager, everything shows green and 'working properly...even for the MAudio card when it was in. If i plug/unplug headphone/mic the device manager goes from red to green indicating it recognizes the connection. This morning, I was in the realtek device manager and selected properties. It takes you to a test area. Oddly enough, I could hear the test audio in my headphones but there was no sound when playing music or streaming video. That test worked off and on and now when I test, there's nothing. It's as if there was some cascading failure and little by little things are shutting down but all the hardware shows green and working properly. There are no conflicts showing with IRQs. This all seemed to start with the HDMI/SVideo connection. I removed that altogether and rebooted but still nothing. I know my headphones are good. My stereo is good and all sound controls are maxed out. Nothing is set to mute. I ran a virus scan with Trend Micro, SuperAnti Spyware, and Malwarebytes and all ran clean. Weird that I could hear the test audio but nothing else and now that doesn't even work. First the MAudio card went silent. The integrated realtek worked for about a day or so then it went quiet. Very odd. Any feedback or input would be greatly appreciated. Ok...two minutes ago I tried the test again and I can hear the tests in my headphones. But, internet streaming and windows media player are still silent.