I bought a second hand DM-24. At some point, I must have hit a setting or something, because the channels now route through Aux and the only way the faders work is if I'm on the Aux 1-2 screen. If I go to the Meter/Fader screen, the faders no longer adjust the volume. Also, the MUTE button on any channel does not work no matter what I do. When I first used this, I didn't have this problem but I think when trying to adjust the Frequency I must have messed something up and now I can't get it back to working like normal. If anyone can offer assistance, I would greatly appreciate it. I basically just want to be able to use the fader screen and the mute buttons.