It is axiomatic that unless all nav aids named in the proceedure nameplate are serviceable, that approach is not able to be flown. Think about a VOR/DME proceedure - take away the VOR, what's left??? or the DME, where are we distance-wise??? Likewise with a twin locator. If both aids weren't necessary, they wouldn't be named, it would be a locator approach.
If one of the aids is not displayed, I would expect Oz AIP ENR 1.5-7 para 1.10.1 (b) Missed Approach would apply .....radio aid fails....its failed alright - you turned it off! Also try ENR 1.5-13 para 1.12.1 descend when "established" - not easy if the aid is not displayed.
Yeah, I know - you're established on the other one, BUT both are named in the proceedure and are necessary as far as the designer is concerned.