My Canon 550ex wouldn't switch on yesterday. Completely dead. Changed the batteries (twice). Still nothing, no indication of life. It was fine last time I used it about a week ago. Is there anything ...
I have a Canon 420EX Speedlite that sometimes won't start up. When it's not working, it behaves as if it didn't have any batteries in it... just totally dead. The odd thing is, it doesn't seem to be ...