Cactus V2s and Viv 285HV not firing

well they all worked perfectly last time i used them, but i had a shoot last night and they just wouldnt fire. the lights still work, but i just cant get them to connect through the transmitters.
i tested them earlier in the day and they worked fine, but i get to the place and they wont fire

i replaced all of the batteries in everything, but they just wont go off

any help would awesome

Did you check the channels? When I had mine they wouldn't fire because one of the channel switches was barely out of place.