How can you tell if a switch on the audio panel -- like ADF1 -- is on or off? Clicking the switch changes it from on to off and vice versa, but the little arrow on the switch doesn't move and you can't tell how it's set.Tom Kent

When you push the switch (mouse click) you turn it on/off. The switch illuminates when it is on.Use the mouse wheel to turn the volume up/down.Multiple switches can be selected.( I guess the reason the arrows do not turn is because of the limits reached in the NGX animations. )Fred.

Fred, thank you very much. Indeed, clicking on the knobs does turn the audio on and off, but they don't light up for me. We're talking about the knobs reading 1-NAV-2, 1-ADF-2, MKR, etc., right? Their appearance doesn't change at all when I click on them. Something I can do to fix?Tom

For those interested in this issue, I contacted PMDG. They asked if the problem occurs on all planes, or just one. I switched from thre 900NGX to the 800NGX and the audio panel works fine on the 800. Will tell PMDG, and if they have any ideas I'll post them here.