Due to the extreme pressures that are put onto bindings while executing turns, all binding screws can work loose. Regularly checking and re-tightening screws as necessary will prevent damage to skis and bindings. Screws can be glued in place with araldite if loosening becomes a nuisance.
NNN Back Country bindings
It is rare that this binding system needs repairs, as one ‘old’ ski tourer commented, even after an 84 day ski tour!
A piece of wire can come in handy to replace a hinge and hold the bail together.
If you lose the locking nut on the cable, use a piece of wire to connect the cable to the clasp that tightens down the cable. You should be able to tighten it down well enough to still have a lot of fun down the home trail doing graceful telemark turns.