Canon 600EX II-RT drops link- HELP!

[Phillyphoto]

Scenarios I have tried: 

Using Canon Transmitter ST-E3-RT as the master and (2) 600 EX II-RTs as slaves.

Using A 600EX as master and B 600EX as slave.

Using B 600EX as master and A 600EX as slave. 

I get the same result of the slave dropping link. The time varies. Sometimes it drops link in 4 mins, sometimes 10mins, sometimes 20 or more minutes. The only way to relink them is by turning everything off and back on.

All channels are the same. Yes, I have scanned for the best connection as well as every other channel and AUTO.

All IDs are the same. 

Not near a wifi-router or airport, I'm in a row home in Philadelphia. 

Using NiMh rechargeables and using freshly charged batteries for every test. Batteries are about 2 years old. 

I have spoken to 2 Canon service reps and neither of them has any idea what the problem is. I really don't have the money to spend on sending everything in for "repair". 

Any help is greatly appreciated, thanks!

[kristieschram]

Me too.  They kept going off during to studio sessions.  The clients loved the session, but said hopefully the next time my lights won’t be broken. Very embarrassing.

[AdamFalgout]

I have 4 600EX-RT's and they constantly drop connection from my EL-1 at wedding receptions. I go turn off the remote flash, turn it back on and they link back up for 1-2 minutes, then they lose connection, requiring manual shut off and turn back on.  I rely on my extra off camera flashes significantly, it's a selling point for my photography, and I would also be interested in some class action type suit. It's a HUGE negative, HUGE headache, and HUGE impact on how professional I look with flashes constantly disconnecting.  I'm a professional, but Canon certainly makes it difficult to appear that way.

[apphoto]

Had this same frustrating issue. 
The solution that I decided to pursue is to use a Godox (XProC or X2)  transmitter (on camera, instead of Canon's transmitter) and also to attach a Godox receiver (X1R-C) onto every Canon flash.   I made this switch in February of this year and have been very happy with the communication reliability in all of my indoor and outdoor events since then.  (I now just use the Canon transmitter to get a channel strength reading before I start, then it just gets turned off and put away).

Godox transmitters are around $70 and the receivers are around $40 (B&H).
The XProC transmitter has a bigger display screen than the X2; however, the X2 also has a hot shoe so that you can both control remote flashes & have a flash on camera.  I have both and use one or the other depending on the situation.

[AdamFalgout]

This is great information thank you for sharing!

[crlyhds]

As frustrating as this is for everyone, a solution is almost impossible. We can all be  mad at Canon but put yourselves in their shoes. Use the flashes/transmitter in a wifi free zone and all work as advertised. Error is being caused by outside interference. If they decided to somehow fix it the only solution, that I can see, would be to change the frequency the flashes operate on. 2.4ghz is way too crowded. Download the free Wifi Analyzer app and you will see how crowded it is. If changing the operating frequency is even possible it would probably be very expensive. Ultimately the cause of all this is the FCC. One of the mandates for the FCC is to prevent one transmitting entity from interfering with another. Clearly they have dropped the ball here. Given the number of users with the problem vs the number of wifi networks, I wouldn't expect much from them. My solution is to use infared. Since I am studio use only it is not a problem. Downside is I can't use those expensive wireless transmitters. So I wish you all luck with this. If anyone comes up with a solution by all means share.

[AdamFalgout]

I disagree, if turning the slave off then on reconnects the sync, it should automatically do whatever it needs to do if the link is lost to re-establish the link, in whatever way it is doing it by power off then on. A firmware update could solve this or make this happen automatically.

[JimOsdale]

Then why is it the Godox transmitters/receivers work just fine, never losing connection? Canon does not care at this point, they have the income from the sales of the transmitters/flashes.

[Steppy]

Because Godox implemented the interface properly!

I use Phottix Laso adapters which are 100% compatible with the Canon RF system and they also work great. They also make (made) a fully compatible controller which also works perfectly, so far...

Canon have simply messed up somewhere. This has most likely only become a problem as modern WiFi systems (including my Apple home pods) introduced what I believe to be new broadcast messages. While these perfectly legal network messages happily pass through my entire WiFi, Ethernet and Powerline networks, they trip up the Canon flash system at the other end.

[ncolarusso]

If one has 3 slaves and needs to make the rounds to reboot the slaves every 3 to 4 shots it kind of defeats the purpose of having a wireless setup. If Canon would recognize the issue then a firmware update would be forthcoming. If no admission by Canon that an issue is present there is no firmware in the works.

[eschrad]

I would just like to report in that I've not had an issue with my flashes dropping sync since I set up my flashes as I outlined in this post.  I know others have not had similar success, but mine have been reliable. Fired every time at this Halloween-themed wedding even as I went in and out of this room to an adjacent room and also outside, switching from linked, to unlinked, to flash off and back numerous times.