RE: K2500XS Sustain Pedal stopped working

IIRC, you can also hold down the sustain pedal while powering up the Kurz. This is to accommodate certain pedals that are "momentary off" as opposed to "momentary on". 

 

 Ideally, you'd want to check the pedal with an ohmmeter across the two points on the plug, see if the pedal switches off and on again to produce 0 ohms (or a tone, if so equipped) when pressed or released.