Another 1DX issue isolated - flash related - but need help replicating

[Sycotek]

Ok so I am going to get my replacement body tomorrow (flew in too late to pick up on saturday). However I have just come back from a pre-wedding shoot this afternoon and the same flash related issue popped up again.

Equipment list:

1DX
600EX RT
EF 70-200 F2.8 L IS USM II
Sandisk 60MB/s 8GB CF and Sandisk 90MB/s 32GB CF (i normally use match pairs but didn't have time to clear the full card prior to the shoot)

Issue:
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Shooting in broad daylight, Direct flash being used for fill, AV Priority, F4, ISO 200-800+ (HTP on), EC +1/3 and FEC -1 2/3, HSS.

Now in single shot mode it works fine. But i had the couple move around a bit so switched to AI Servo and this is where the issue begins.

The camera literally locks up - screens are powered, vf is powered but the lens doesn't rack in portrait or landscape, depressing either shutter does nothing, powering off the body does nothing.

Turning the flash off and turning the body off fixes the issue for a few frames but after a good 20 frames it repeated the issue.

-Switching lens to a 50mm and the issue didn't come up again.
-When this first happened overseas I was using the same configuration 600EX with 70-200.
-On a 7D this same config doesn't have the same issue.

Thoughts?

 

[neuroanatomist]

Does it only happen with those cards, and if so, which is in which slot and how is your recording set (switch when full, record to multiple, etc.)?

Could it be a flash temp issue? When it's locked up, what happens it you press the test button (ready lamp)?

I have everything on your list, so I can try to replicate.

 

[Sycotek]

I had both 32GB cards in overseas when this originally happened - the 8GB in slot one today when it happened so its not the cards as far as I can see.

Flash temp unlikely (no red lcd) and dhooting nearly -2ev under so very very little flash added.

I haven't had time to run a controlled test at home as yet - i didn't think to try the ready lamp as I was struggling to get the system up and running with clients waiting for my gear to work...

Thanks for trying this out in advance.

 

[Sycotek]

Ok, so - replicated indoor with room lights, not the best test as the servo has issues in this room focusing normally. Remembering issue occurs during midday light on my unit.

-When it locks up, flash fires from test button.
-If i continue to mash the shutter over and over after a good 15-20 presses the lens suddenly springs to life.
-It did however take 23 shots before the issue occurred - i started at -3fec and ramped up to -1fec (not that it really matters)

Indoor settings, M: 1/[email protected], iso 6400 (I wasn't paying attention to shutter speed too much was just getting it to +1EV)

I will try my other 600 EX and see if that is the culprit tomorrow if I get the time.