MAZAK Variaxis 200 won't home properly.

Hello everyone,
I'm working on a mazak variaxis 200 (Mazatrol 640m year 2000) and for some reason this puppy won't home nor will it make a tool change.
Whenever I attempt to home Z it won't go past 8 inches above the table.
If I attempt to make a tool change the spindle head will travel beyond the area it is supposed to.

I've fiddled with M8 and M9 parameters with no succes, what am I missing?

Thanks in advance