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 that can be done?

  • Can analysis be worthwhile? Is the speedlight really dead? – rackandboneman Oct 8 '19 at 7:09

After trying as few things and playing around with the flash with no success, I found the following thread on the web.

The advice given is :

Rub all the battery contacts very briskly with a clean rag that is just ever so slightly damp.

I actually works! To rub the terminals inside the battery compartment I wrapped a thin, slightly damp rag around the eraser end of a pencil and gave it a few spins. The terminals didn't look corroded or damaged. Afterwards the speedlite switched on, good as new.

  • Don't forget that you can accept your own answer. Congratulations on having fixed the issue with your flash! – Francesco Jan 21 '13 at 22:43
  • Sometimes rubbing all the contacts with the eraser end of a pencil also works at cleaning off the crud. – Pat Farrell Jan 22 '13 at 1:53
  • as per the advice cleaned the contacts with damp cloth and pencil and switched on and off with batteries removed seems to work ok now – user82540 Mar 8 '19 at 10:54

Another solution I saw (can't find the original link anymore), was to take the batteries out and switch on and off again. Apparently this 'resets' the electronics.

I don't know if this actually works. I'm just adding it here as something to try for people who search this question.


All I know is I was just about to go out and buy a new Flash Gun for my 5D MkIII as both my flashes had failed, the problem I realised was I hadn't used my Flashes for a couple of years, they were not well used but both my 580EX ii and my 430EX failed to even show a glimmer of a spark. Then I read about cleaning the contacts with a slightly damp cloth wrapped around a pencil rubber(eraser). I am now the proud owner of two working flashes, and a few hundred pounds better off.

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