# 600EX RT & ST E3 RT - Radio Stopped Working Issues



## hawkins132 (May 15, 2012)

I have two 600EX and the ST E3 RT. I've experience various situations (10% of the time) where the radio transmission doesn't work or stopped in the middle of a shoot. I can't exactly replicated it yet, but in all cases the Connect Ready Light on the upper left corner are lit; which should indicate connections are online. 

In all cases my batteries are freshly charged, and I don't do consecutive flashes and don't hear beeps. The Radio Transmission stops working sometimes when:

1. I switch from ETTL to Group mode, and setup up a mix of ETTL and Manual, and switch between difference modes even more (I like to experiment!)
2. When my flashes are in sleep mode, I press the shutter button half way to wake them up, then no slave flashes triggering anymore

*I fix this by:*

1. Sometimes turning the Master or Slave flash off then on again.
2. Or sometimes just unplug and plug the Master into the hot-shoe again.

*Possible Cause:*

I read the troubleshoot section throughly, and it indicates the slave may not be triggered when the Master is not *FULLY *plugged into the hot-shoe. So this is possible as replugging the Master does seems to fix it. However this is misleading as:

1. I always lock the hot-shoe, so it "should" be firmly connected.
2. It doesn't explain why sometimes turning the flash off and on again will fix it
3. The ready light is on, which should indicate connections are made
4. Master is fully functioning and flashing still

I'm wondering anyone out there having similar radio connection inconsistency issues.

Aaron


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