On Monday 06 March 2006 19:07, baldobe wrote: Hi Bal. That sounds like the sort of thing you'd expect from a bad ground/earth/return connection. For instance. If only the left and right channels were connected, but the screen was disconnected, that is the sort of sound (more of a loud hum) that you would expect. It is worth checking that the ground/earth connections are good, on both the computer, mixer, and amps That is for the 240volt power connections. Also when the computer is switched off, try removing the line output from the computer, and seeing if anything changes. Then put it back, and remove the line input, and see for changes. I presume the screw is in to hold the soundcard in place, but there is so much metal in contact, that, that shoudn't be the problem. It might be worth trying different cables to connect from the computer to the mixing desk, just in case there is a faulty one. PLEASE. Don't electrocute yourself in the process. Nigel. I get that problem on FC2 with an Ensoniqs ens1371 card until I mute IEC958.