I have a roland vs 2400cd and am a newbie to home recording.In trying to understand too much too quickly I seem to have pressed some buttons that I should have left alone.It seems I am unable to get any response on on my imput needle from channels 7 & 8 I can record on all the other channels but not 7 & 8.there is zero movement on the needle and I can,t figure out what it is that I,ve done.hope one of you can sus this for me,before I go bald ,I,m pulling my hair out with it. It was working fine before.