Miller dynasty 200dx

I have an older dynasty dx and the machine still Welds great however in the fold down door where the control buttons are the button that controls the output from on to remote etc.... Is non functional... Every now and then I can push it 40 or 50 times and it may change lol. I've been told this machine was made prior to some type of change they made to this control board so they no longer even service it. However like I said the machine still Welds great and if I'm stick welding with it I just clamp the foot pedal all the way down (since the default output is remote)and it works fine. That being said I think the only issue is this button or something if that nature so my question is.... How would one go about checking this out and repairing it? Thanks in advance.... Dale

Get a remote control box. has a on/off switch and a control pot. Some people call them ditch boxes.

Gotcha..... Haven't thought about that

Do you have a picture?
Could it be the actual button is just a surface mount button behind a printed overlay?
If it's made that way a decent electronics shop could probably swap out the button for a small amount of money.