I tried pulling up on the knobs. (the box is together, all screws in place fyi) and they seem to move about a centimeter up, but there is no give after that. I pulled pretty hard but it doesn’t seem like it wants to pop off, or is designed that way?? I don’t think it would require me to use a ton of force to remove and from what you say, I don’t think it’s right if it doesn’t just “come off”

What else should I try? Do I need to remove anything special, or loosen what looks like a washer-type nut below the knob, before I do this? I tried pulling on all knobs and they don’t seem to want to just come off, so I don’t think they could all just be “stuck”.

Is there a guide or method to removing the circuit board from the backside? Do I have to take off the knobs and is it just a simple turning of them? I don’t want to crack anything plastic, or strip off some threads or something similar. The pots are the underside of the knobs correct?

Thanks again for the response.