travisvwright wrote in post #18296401
Logically I would say no. But I'm going to test it anyway. Maybe Saturday.
I agree, if HSS/SS will not work without the sync cord connection when channels B and C are switched on, why should it work with the sync cord connection given the same settings. It doesn't seem to make a lot of sense.
But your image of the TX settings for your last failed attempt (cord connected) prior to updating the TX firmware (that delivered the black band images) showed your settings that time were in fact the same as Nixland's (i.e. B and C were 'off'). So the settings were not in fact the same for the with and without sync cord trials.
There's just a slim possibility that these differences in settings carried over to your latest (post firmware update) attempts and explain why you still can't replicate Nixland's results. Look forward to finding out when you have had the chance to take another look. 
David.
Comment and (constructive) criticism always welcome.