Canon 580EX Flash will not fire. Being shot on a Canon 5D Mark III.

[PhotoExpression]

The light  does not start out green and stays red on the 580EX Flash. It doesn't even go into a sleep mode when not activated for a length of time.  Fresh batteries does not make a difference.  It will allow me to change settings but it won't fire. The infra-red displays it's test light but the flash will not discharge even when it demands it.  It is not on slave or wireless settings.  Nothing makes the flash go off, even the test flash.

[TTMartin]

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@simplyouphoto wrote:

I decided that the bulb was burned out & not worth the repair cost. I replaced it with the new Canon flash. It works awesome! I still have the issue with it flashing at a rapid speed at random moments & then I have to wait before the camera is usable again but since both flashes did this, I"m guessing it's user error. 

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The flashing at rapid speed at random moments sounds like focus assist. If you have a flash that has IR focus assist like the 580EX and this is occurring it sounds like a settings issue. Lower end flashes starting with the 320EX I believe strobe their flash for focus assist. 

What model is your new flash?

[TCampbell]

The rapid pulse of flash that provides near-continuous light is typically activated by pressing the depth-of-field preview button on the camera (the location of that button varies by model.)  It's usually on the front of the camera body very close to the lens mount. 

[simplyouphoto]

I have the 600 EX-RT flash. Everything I've read says it's a focus assist beam or that I'm pressing the depth of field preview (I own the Mark II 5d. It rapid fires & then the viewfinder goes a bit darker & the shutter button won't work. 

[Samiamphoto1569]

thank you....

i have a certified canon camera  fixer here in miami.

i will drop it off to them first.