Heidenhain 145 trouble

[kck63]

I am having trouble with my Heidenhain 145 r2c3 Bridgeport mill. My problem is the handwheel button seems to be sticking. After I hit the handwheel button and then go to another function (man. run ect.) the light over that button lights up but the screen stays on handwheel . Then if I go back to handwheel it does not work. Is it a bad relay? Any Ideas??

Thanks

[gus]

I have had that trouble before, but never tracked it down, usually went away quickly. I think it may have to do with an unrelated error condition