So where can you use a scope to check the phases, i.e the connection point?? Also, if you can get a scope in there with the engine running, why not just use a meter (AC setting) and go phase to phase?
I bet its the diode pack, although Im not sure if these can be obtained on their own?
As Nomad said, a breakdown here could result in a lost phase which under normal circumstances would proberbly not be noticable. Indeed IIRC Suzuki used to run the old GS series bikes with just two phases until you switched the lights on which connected the third.
I'd been pondering the same thing and was going to post but you beat me to it. Interested to hear a reply on this one.

maybe someone could enlighten me.