Cactus V2 mod for 100% reliability
I recently bought a used set of 4 Cactus V2 receivers and a transmitter. Like many others, I was unhappy with the number of times the receivers failed to fire the flash. New batteries and cleaning the contacts didn't help enough. I noticed that although the flash didn't fire, the LED on the V2 came on, AND THE FLASH LED LIT, as if the flash got the signal but it wasn't strong or long enough to fire the flash. I traced the circuitry and found what I believe is the problem. There are two diodes with the anodes connected to each side of the flash connections and the cathodes joined at the SCR anode. This makes no sense to me. I cut the 'ground or common' wire to the flash connections and added a single diode from the wire to the V2 battery negative. Now the triggers fire the flashes 100% of the time.
Here are a couple of photos that show the mod, easy to do if you are handy with a soldering iron.
Note it is your responsibility if you do the mod and the triggers are damaged.