Urggh.
I have a Mamiya 645, a fairly basic lighting rig (two softboxes with IR sensor) also a Nikon Speedlight (I have 3 Nikon 35mm cameras).
Generally the Mamiya works mounting the IR sensor onto the hotshoe. I find 7 to 8 out of 10 shots trigger the flash fine. I found that depressing the shutter very slowly helps to make sure it fires I assume some sort of contact issue. But last week it was hopeless. Not firing at all. Although pressing the little manual trigger button with my finger always works (so not a battery issue with the sensor).
I then thought about mounting the Speedlight on the side of the Mamiya. Normally I wire up a sync cable and trigger it that way (only to trigger the softboxes). The flash is now playing up so my assumption is that I have fried it (although I have seen conflicting advice about this about voltage and so on). I think I had the flash in the wrong mode. Afterwards I also tried again with the sync cable, but the flash was cranky/patchy and turning itself off.
I am happy to buy a new flash (although I think I would rather go with non dedicated than replace the SL). Of course I will need one if the SL is kaput.
I also own a Cactus V5 TX/RX which I completely forgot I had, so I can try that next of course.
If anyone has any sage advice I would love to hear it, but I also just needed to vent
(things were compounded as I had left the camera in Multi exposure mode and it took me far too long to work this out, I was worried the winders on the film backs weren't working properly).