No sound from tweeters - is it the tweeters or crossover at fault?

Hi everyone. Recently purchased some B&W CM5 speakers. The tweeters are not working on both speakers. I have tried disconnecting the bi-wire link and only amplifying the HF post (at low volume of course). No sound at all. Is there a way to tell if it is the tweeters that are bad or if the problem lies with the crossovers?

Along those lines - I have looked at the B&W parts store at tweeters and crossovers. It appears that the crossover for the CM5 S2 is actually cheaper than the regular CM5 crossover. If it was determined that the crossover was at fault do you think its likely that I could use the cheaper, newer crossover?
Thanks!