Speedlite 600EX-RT link drops - please help if you can!

[gwynnewade]

I suddenly have the same problem a couple others have mentioned.  I use an ST-E3-RT to link three 600EX-RT flashes with a 5D MIII.  Recently the link started randomly dropping on all the flashes (after some random amount of time from 1.5 minutes to about 4.5 minutes).  The only way to fix it is to turn everything off and reset each flash to slave.  Not good during a photo portrait session since it happens multiple times.

I have tried a ton of troubleshooting.  I used to shoot weddings so I have 2 cameras and two transmitters.  I've tried all combinations and the link drops regardless of the camera or transmitter and even if the transmitter isn't on a camera (hand held for test).  Both transmitters drop. I tried several different channels and auto - no change.  I tried each flash by itself to see if is something with 3 flashes - no. Same problem with only one.  I have 4 flashes and I tried the 4th just to see - same problem. 

One last piece of info.  When the link on the flash drops, the light on the transmitter still shows green (so it thinks it is linked).  Turning on and off the transmitter doesn't re-sync the flashes.

This seems crazy.  It can't be the camera (I even tried it with a new R6 that my husband got - same issue), because it happens when not connected to the camera.  Why would both transmitters go bad? Why would all 4 flashes go bad.  I don't know what else to try.

Any ideas, I'm pretty desperate at this point.

[sfogel2]

Other protocols in that band like WiFi and BlueTooth don’t “succumb” to RFI. They retransmit if needed and keep the session alive.  

[BillWayToday]

EXACTLY!!!!!   I keep hoping Canon will do a SW update to accomplish that!  

[sfogel2]

Yeah, but first they have to acknowledge the problem and I've been trying for weeks to get them to do that. Have to figure out how to get them to witness the problem, because they couldn't see it with my 4 flashes and ST-E3-RT transmitter at either of their repair facilities. 

Trouble is, even though one of their techs tried for a couple of days with my flashes, they don't have much incentive to try hard with the 600EX-RTs because those are end of life and no longer supported. They need to see the problem with the EL-1's. The EL-1s do have the same problem. My experiments proved it.

[BillWayToday]

I'm going to be doing an event shoot at a Marriott and I'm thinking to use optical, since radio isn't reliable.  Back to optical!  I own 5 radio Canons and they're useless.  

[sfogel2]

Hey, BillWayToday...gimme a call and I'll tell you how I was able to get reliable off-camera E-TTL for my subject and have the flashes placed around the room fire reliably. Steve @ 650.698.8672 after 10:00am PDT.

[sfogel2]

For my recent event I decided not to use optical, since it's really easy to get in the way of the line-of-sight. All a guest has to do is stand in front of one of the flashes and it won't fire.

I ended up triggering the "slave" flashes with PocketWizards. The down side of that of course is that they all had to be on manual and if I wanted to raise or lower the intensity I had to run to each one. But It worked out.