Yongnuo RF 603C Flash Triggers Help

Hi guys and gals,

I'm new too the forum's here, I'm Seán from Ireland, just recently got the Yongnuo RF 603C wireless flash triggers. I'm having trouble getting them to fire my flash. I've set them up right as far as I know from what the manual says.

I put the two transceivers onto channel 1 as stated in the manual as well as the K & E switches too as shown in the diagram. I also swtiched my camera flash to manual mode too and nothing, no response from the flash. I've got a Canon 40D and a Canon Speedlite 580EXII.

Would appreciate some help with this thanks .

Do you get green lights at all when you put one on your flash and one on your camera?
Also, with those and RF602s, low batteries won't allow them to fire (as well as low battery power in your flash)

My dad and I each have RF603c's and have no problems. If the flash doesn't fire and they are on the same channel, common issues could be one or both of the triggers are off, flash went into sleep mode or it's off, etc.

Is your 580EXII in slave mode? You need to turn off the Canon wireless system, or else the flash ignores the hotshoe.