is yours missing? If it's still present they are pretty easy to fix. It's been about 5 years since I've worked on one but I remember thinking how easy it was to fix.
You can make one VERY easy. Use a project board, the circuit is simple.
Follow my lead as I try to modify mine!
I have pictures posted of the board (I'll post one of the underside for you)
I'll have a material list with part #'s from Mouser Electronics as soon as I confirm the parts I ordered will work.
You will have very little cost in the components.