It sounds like you had it in the slave mode. The only time my 580 and or 430 blinks is when it is slaving. It should reset to default ETTL when you pull out the batteries for 1 minute or so.
I have tried putting it in ETTL, Manual, Slave, Master, and took the batteries out for 5 minutes -- it still is not blinking. The flash unit seems to be working -- but, no red blinking light in any mode.
Hi, As Sparkey2 implied, the only time that the red lamp in the lower part of the front of the flash body flashes, is when the unit is in slave mode (it can be either ETTL or M but it must be slave). ie the word 'slave' should appear on the screen and be steady (the text not blinking). The rest of the time it should not flash at all. (The projected red line pattern for focus assist is a separate function.)
When it is flashing red, you need to be able to see those flashes from the master position - otherwise Canon Wireless may let you down. HTH
hi, i had the same problem with my 550EX. Flash works on hot shoe but no blinking under slave mode. no response either...too bad i think we need to take it back to canon
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Andrew Chan http://chanandrew.com/gallery.htm
'Once you learn to appreciate, everything is Photogenic.'