Hey tnicoson!!
Many thanks for your detailed reply!
I know a little about how the keys work and I've come across many things with the same rubber dimple and contact design for buttons in the past, luckily I rather enjoy fixing broken electrical items so now you've confirmed my original suspicions that it is a physical issue and not a setting I'll be fixing it myself.
The thing is loads of people had told me it's a setting that you can adjust but what setting appeared to be unknown! Which is why I came to this forum thinking one of you is bound to know how to unset it lol. I don't mind having to take it apart because while I'm at it I'll replace all of the rubber's because I know from other things that they do perish. It's a similar design in the older iPhone's for the home button, I have fixed many of those in the past haha.
Anyway thanks again!
P.S one question if you don't mind please? How old are the WK-3700's? There is a date on the box of 2005 is that right? What would you say they're worth now? I paid £50 for mine boxed too and to tell you the truth I thought I over paid :/
-Rusty.