600ex-rt not firing

[Kmlewis]

All of a sudden my 600ex-rant doesn't fire. It communicates with the camera (wakes up when half pressing the shutter, f-stop indicator changes when I change it on the camera) but it won't fire when I take a picture.

It fires when you press the flash button on the unit itself, so it's not the bulb. The contacts appear clean and other triggers work on my hot shoe. What gives? And is it possible for me to fix this?

[TTMartin]

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@Kmlewis wrote:
All of a sudden my 600ex-rant doesn't fire. It communicates with the camera (wakes up when half pressing the shutter, f-stop indicator changes when I change it on the camera) but it won't fire when I take a picture.

It fires when you press the flash button on the unit itself, so it's not the bulb. The contacts appear clean and other triggers work on my hot shoe. What gives? And is it possible for me to fix this?

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Check the external flash control setting in the camera's menu. Most likely it is disabled some where in there.

[Lui-G]

I am having the exact same issue with my 600EX-RT's. I have two which i use as slaves on my Canon 5D Mark IV with a brand new ST-E3-RT Transmitter as a master. They were both working perfectly fine, firing in every shot. Now one of the flashes (Slave B), only fires once every 4-6 shots. Batteries are good,and it is enabled in my external flash settings in the camera. Any idea why this is happening ? 

[RobertTheFat]

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@Lui-G wrote:

I am having the exact same issue with my 600EX-RT's. I have two which i use as slaves on my Canon 5D Mark IV with a brand new ST-E3-RT Transmitter as a master. They were both working perfectly fine, firing in every shot. Now one of the flashes (Slave B), only fires once every 4-6 shots. Batteries are good,and it is enabled in my external flash settings in the camera. Any idea why this is happening ? 

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I assume this is in a studio setting. If you exchange the positions of the two slaves, does the problem follow the device or stay with the position? If the former, try resetting the flash unit. If the latter, try a different channel, in case there's some sort of RF interference that you can't control.

[Lui-G]

I tried everything to no avail. I spoke to Canon who suggested i bring it in for repairs, so i did. Its going to cost about $200 including shipping. I have no choice as i need it for a job ASAP. Thank you anyway for your help. 

[Dina_Ezzat]

i have the same problem, the camera can feel the flash and even changes settings of the flash from inside the camera (5D MARK ii). the flash fires when i press the test button i cleaned all the sensors in the camera and the flash itself. changed the batteries from rechargeable to normal alcaline, tried the flash on another camera but nothing changed. maybe there is something in the settings i cannot see that happened by mistake!!! 😞

Please help urgent !!!!!!

[Johnny717]

More than likely the hotshoe accessory on the flash causing the issue.

[lavallie]

No, I switched to a different flash and not a single failed flash.  It's in the 600ex-rt somewhere...

[Dina_Ezzat]

Finaly i got the flash fixed, the engineer opened it and found out that the red wire was cut and he fixed it ! 🙂