I recently purchased a Nissin i40 flash, hoping to use it with some Yongnuo RF-603N II wireless flash triggers that I already owned. The triggers worked fine in manual mode with my A7 and an old Metz flash I had left over from my µ4/3 days. So I was dismayed to learn that the Nissin wasn't compatible with the Yongnuo triggers because the ground pin on the flash is too far back to make contact with the ground pin on the triggers. I found some work-arounds on the Internets that involved mounting a carved-up adapter between the trigger and flash. But that approach didn't appeal to me. Then I noticed that the trigger has some grooves in the top surface, and I wondered if a small gauge wire placed in the center groove might allow an electrical connection between the flash and trigger. And a paper clip seemed to offer a perfectly-sized wire. Sure enough, it fit snugly, and made a solid electrical connection between the flash and trigger. A little bending of the paper clip... And some electrical tape... And hey presto, I now have a perfectly functioning flash/trigger combination! I have now mounted and unmounted the flash repeatedly, and so far it makes a reliable connection every time. In the motorcycle world, a good repair that uses some cheap stuff you already have lying around the house is called "penny-tech" and this fix fits that description perfectly. And the bonus is that I can also use the Nissin as a TTL flash when mounted on the hot shoe of my A7, and as a wireless slave (without any trigger) with my RX100III. So if any of you want to use a Nissan i40 with your Yongnuo flash triggers, this set up works, and it won't break the bank.