speedlite 580ex II flashes at full power

[vencislav95]

HI, everyone 🙂
I have a canon speedlite 580ex II. But suddenly when I had made photos it started to flashes at full power.  Help me. What could be the problem?

[hsbn]

More information would be helpfu. What camera? what is your shooting mode? what is the flash mode? What make you think it shoot out at max level?

[vencislav95]

My camera is Canon 5D mark 2. Shooting mode was AV or M. The flash was in manual mode. That day I used all flash modes and it worked. But after that, they did not. My photos was overexposed. 😞 

[Skirball]

I don't understand the issue.  If you're in manual mode then it's up to you to select the flash power.  If it's over-exposing then simply move the power down.  If it's over-exposing in eTTL then check your flash exposure compensation on your camera.

[hsbn]

Like Skirball said, if you shoot manual, then you are in control of the power out put. If it is overexposure, then lower your flash output.  When shooting moving subject (or you move around), you'll to reduce the flash power if the distance between you and your subject decreases.

[vencislav95]

No, no, no... I have made a few photos with this options. Everything was fine. But suddenly my flash is going crazy.

1/16 or 1/2 no differance = full power/ full flashes.

[Skirball]

Ah, got it.  Does it work properly in eTTL?

First thing I would do is pull it off and have a look at the contacts; any gunk or rust?  And re-install it on the camera, sometimes if it's not firmly lined up and locked on weird things happen even though it still fires.  Finally, I'd put in new batteries, odd things happen when the battery is low too (though if the batteries are low it wouldn't be able to fire at full for very long).

A final last ditch effort is to use it in full manual.  If you put tape over all the contacts except the center then the camera won't even recognize it other than to fire.  See if that works as a temporary solution then we can work backward to maybe figure out the problem.

[vencislav95]

Both eTTL and manual mode does not work.  The flash works on full power. Contacts area are clean. I have changed batteries several times but no result. I have tested it on canon 30d but it`s the same. 

[hsbn · Accepted solution]

Do you use pocket wizzard or other radio trigger by any chance?

I found this document "http://lpadesign.com/580EXII.pdf" I don't know if it could be your problem or not. But here is the excerpt:

"The symptom of the failure is that the 580EX II will no longer output controlled amounts of light. It will
only output full power dumps. This full power dump will happen even on a pre‐flash, therefore leaving
no stored energy within the capacitor left for a main flash exposure.
The testing quickly revealed that an IGBT (transistor) within the flash is damaged. This part is made by
Renesas (part # RJP4301).
The IGBT is used to turn off the flow of current through the flash tube when the desired amount of light
has been reached. This IGBT is also used to control (modulate) the brightness of the light when in HSS
(High Speed Sync) with the help of a fiber optic cable feeding a light sensor within the main body."

[Rez]

Hi,I have orderd the part you mentioned ,Could I do the replacment or should be done by a qualified electronic engineer? thanks already