Patches and discussion for Ensoniq VFX family

Just fired up my VFX-SD to discover the "sustain" seems to be stuck
permanently on. Any notes I play stick and do not stop. 

I've tried pulling a pedal into the footswitch (usually sustain)
socket, but it makes no difference.

Anyone have any ideas? 

Is this possible one of those "keyboard design fault" problems?

Thanks!
C.